SafeWork NSW v Grasso Consulting Engineers Pty Ltd; SafeWork NSW v Ignazio Grasso

[2019] NSWDC 792

District Court

New South Wales

Medium Neutral Citation:	SafeWork NSW v Grasso Consulting Engineers Pty Ltd; SafeWork NSW v Ignazio Grasso [2019] NSWDC 792
Hearing dates:	29-30 April 2019; 1-2 May 2019; 6-10 May 2019; 13-17 May 2019; 3 June 2019, 24-25 June 2019
Date of orders:	18 December 2019
Decision date:	18 December 2019
Jurisdiction:	Criminal
Before:	Scotting DCJ
Decision:	1 The prosecution has proved all of the elements of the offence beyond reasonable doubt. 2 I find Grasso Consulting Engineers Pty Ltd guilty. 3 I find Ignazio Grasso guilty. 4 I will list the matters for sentence on a date convenient to the parties.
Catchwords:	CRIME – prosecution – work health and safety – duty of persons undertaking business – duty of employers – risk of death or serious injury
Legislation Cited:	Corporations Act 2001 (Cth) Criminal Appeal Act 1912 Occupational Health and Safety Act 2000 Work Health and Safety Act 2011 Work Health and Safety Regulation 2015
Cases Cited:	Baiada Poultry Pty Ltd v R (2012) 246 CLR 92 Bulga Underground Operations v Nash [2016] NSWCCA 37 Carrington Slipways Pty Ltd v Callaghan (1985) 11 IR 467 Director of Public Prosecutions v JCS Fabrications Pty Ltd and JMAL Group Pty Ltd [2019] VSCA 50 Director of Public Prosecutions v Vibro-Pile (Aust) Pty Ltd [2016] VSCA 55 [3]-[6]. Dunlop Rubber Australia Ltd v Buckley (1952) 87 CLR 313 Genner Constructions Pty Ltd v WorkCover Authority of New South Wales [2001] NSWIRComm 267 Inspector Ching v Bros Bins Systems Pty Ltd [2004] NSWIRComm 197 Kirk v Industrial Court of New South Wales (2010) 239 CLR 531 Laing O’Rourke (BMC) Pty Ltd v Kirwin [2011] WASCA 117 R v Board of Trustees of the Science Museum [1993] 1 WLR 1171 R v Commercial Industrial Construction Group Pty Ltd (2006) 14 VR 321 R v Lavin [2019] QCA 109 R v Nelson Group Services (Maintenance) Ltd [1998] 4 All ER 332 Royall v The Queen (1991) 172 CLR 378 Simpson Design and Associates Pty Ltd v Industrial Court of New South Wales [2011] NSWCA 316 Slivak v Lurgi (Aust) Pty Ltd (2001) 205 CLR 304 Smith v Broken Hill Pty Ltd (1957) 97 CLR 337 Tangerine Confectionery Ltd and Veolia ES (UK) Ltd v R [2011] EWCA Crim 2015 Thiess Pty Ltd v Industrial Court of New South Wales (2010) 78 NSWLR 94 Universal Telecasters (Qld) Ltd v Guthrie (1978) 18 ALR 531 WorkCover Authority of New South Wales v Kellogg (Aust) Pty Ltd [1999] NSWIRComm 453 WorkCover Authority of New South Wales v Kirk Group Holdings Pty Ltd (2004) 135 IR 166 WorkCover Authority of NSW v Atco Controls Pty Ltd (1998) 82 IR 80
Texts Cited:	Australian Standard 2601-2001: The Demolition of Structures How to Manage Work Health and Safety Risks 2011 Safe Design of Structures Code of Practice July 2014
Category:	Principal judgment
Parties:	SafeWork NSW (Prosecutor) Grasso Consulting Engineers Pty Ltd (Defendant) Ignazio Grasso (Defendant)
Representation:	Counsel: B Docking (Prosecutor) S Meehan (Defendant)   Solicitors:     SafeWork NSW (Prosecutor) Kreisson (Defendant)
File Number(s):	2018/746382018/74733
Publication restriction:	None

Judgment

Introduction

1. Grasso Consulting Engineers Pty Ltd (GCE) has pleaded not guilty to a charge that, between 7 March 2016 and 19 March 2016, as a person who had a health and safety duty under section 19(2) Work Health and Safety Act 2011 (the Act), it failed to comply with that duty and thereby exposed Paul McClutchie and Nigel Hayward, to a risk of death or serious injury contrary to section 32 of the Act.

2. Ignazio Grasso has pleaded not guilty to a charge that, between 7 March 2016 and 19 March 2016, as a person who had a health and safety duty under section 27 of the Act, he failed to comply with that duty and thereby exposed Mr McClutchie and Mr Hayward to a risk of death or serious injury contrary to section 32 of the Act.

3. Messrs McClutchie and Hayward were employed by Rosenlund Contractors Pty Ltd (Rosenlund). On 19 March 2016 Mr McClutchie was operating a long reach 70 tonne excavator (the excavator) to demolish the roof of the Sydney Entertainment Centre in Haymarket (the premises), which was also known as the Qantas Credit Union Area (QCUA). Mr Hayward was working as his spotter and was in contact with Mr McClutchie by two-way radio. At about 10am whilst Mr McClutchie was demolishing part of Bay 5, the remaining roof structure unexpectedly collapsed. One of the main trusses in the roof structure collapsed onto the cabin of the excavator, trapping Mr McClutchie inside. He escaped by kicking out a window of the excavator and was unhurt. Mr Hayward was standing under the protection of the concrete structure, but had in the period of the charge, from time to time, stood on the arena floor and close to the excavator.

4. GCE admitted that Elements 1 and 2 of the offence pleaded against it, which are set out at [201] below, were established beyond reasonable doubt on the evidence.

5. Mr Grasso admitted that Elements A and B of the offence pleaded against him, which are set out at [202] below, were established beyond reasonable doubt on the evidence.

6. The issues in the case against GCE are:

1. Did GCE fail to comply with its health and safety duty by failing to take the steps particularised in [8] of the Amended Summons? (Element 3);

2. Did GCE’s breach of duty expose Mr McClutchie and Mr Hayward to a risk of death or serious injury? (Element 4).

7. The issues in the case against Mr Grasso are:

1. Did Mr Grasso fail to exercise due diligence to ensure that GCE complied with its duty by failing to take the steps set out in [12] of the Amended Summons? (Element C);

2. Did Mr Grasso’s breach of duty expose Mr McClutchie and Mr Hayward to a risk of death or serious injury? (Element D).

8. The prosecution alleges that GCE was retained by the demolition contractor to provide it with structural engineering advice to ensure the safe demolition of the premises. The prosecution alleges that GCE’s advice and/or conduct led to the premises being demolished in a way that resulted in a risk of an unplanned collapse of the roof structure, which actually occurred on 19 March 2016.

9. The prosecution alleges against Mr Grasso that he should have exercised due diligence by ensuring that GCE took the steps particularised to comply with its duty.

10. GCE’s case is that the roof structure of the premises was not demolished in accordance with its advice and that the prosecution was on notice of this from, at least, about October 2016. GCE contends that when the prosecution qualified its expert witnesses in November 2016, that it did not ask them to provide an opinion as to whether there was a risk of unplanned collapse of the roof structure, if GCE’s advice had been followed (the GCE advice alternative). Accordingly, GCE says that the prosecution cannot prove to the required standard that GCE’s advice was a significant or substantial cause of the workers being exposed to the risk of serious injury or death.

11. Mr Grasso’s case relies on the defences available to GCE.

Facts

General background

The relevant parties

12. GCE conducted a business providing Civil Engineering, Structural Engineering and Project Management services. Mr Grasso was at all material times the sole director and secretary of GCE and a structural engineer registered with the Board of Professional Engineers of Queensland. GCE had no employees and Mr Grasso provided his services as an engineer through GCE.

13. In or about 2014, Lendlease Building Pty Ltd (Lendlease) successfully tendered for the redevelopment of the Darling Square site in which the premises were located. It was the Principal Contractor, as defined by clause 293 of the Work Health and Safety Regulation 2015 (the Regulations), for the demolition of the premises and the redevelopment of the site.

14. On 19 June 2014, H. Hassarati & Co Pty Ltd (Hassarati), a licensed demolition contractor, provided a lump sum tender to undertake the demolition of the structures on the Darling Square site, including the demolition of the premises down to its foundations. Hassarati did not ask GCE to be involved in the preparation of its tender to Lendlease for the demolition work. It was not Hassarati’s practice to obtain external advice to develop tender submissions.

15. On 25 November 2014 Lendlease accepted Hassarati’s tender.

16. GCE was engaged by Hassarati to provide services on an ad hoc basis. There was no contract between GCE and Hassarati specific to the premises and the scope of services to be provided by GCE was not recorded in writing. GCE charged Hassarati a fee based on an agreed hourly rate and it sent Hassarati a tax invoice for work done on an intermittent basis. GCE first became involved in the demolition of the premises at about the time when Mr Grasso was invited to a site inspection on 16 March 2015.

17. In December 2015, Rosenlund was subcontracted by Hassarati to demolish the roof of the premises, using the excavator, excluding the primary and secondary trusses (T1 to T8)[1] with the intent that they would be left in situ. Hassarati did not ask Mr Grasso to advise on the selection of Rosenlund as its subcontractor.

The demolition of the premises

1. Described at [21] below.

18. At all relevant times, it was intended that the demolition of the premises would take place in the following stages:

1. Soft strip out. This involved the removal of the furniture, plaster walls and ceilings and the floor coverings, leaving only the parts of the premises that were constructed of steel or concrete, so as not to contaminate recyclable materials;

2. Demolition of the steel roof structure, except for the primary and secondary trusses (T1 to T8), with the use of the excavator;

3. Sequenced oxy-acetylene cutting of the primary and secondary trusses from above by workers working from elevated work platforms allowing the cut sections of the trusses to be removed by a crane positioned outside of the arena;

4. Demolition of the concrete arena.

19. The incident described in [3] above occurred during the demolition of the roof structure or in Stage 2 as described in the preceding paragraph.

The roof structure of the premises

20. The premises had a roof structure that covered an area of approximately 8,858m2, with dimensions equivalent to 107m by 90m wide. The roof structure was constructed of steel members covered by sheet metal roofing. It was supported by its own weight on a concrete box culvert structure at the perimeter of the building. There were no columns in the arena to support the roof structure.

21. The main members of the roof structure were four pairs of trusses. Two pairs of primary trusses (T1 to T4) were oriented along a north-south axis. Two pairs of secondary trusses (T5 to T8) ran east-west. The primary and secondary trusses supported a grid of primary beams, secondary beams and intermediate trusses. The primary and secondary beams supported steel purlins and klip-lok™ steel sheeting. Ancillary fixtures, including a catwalk, high voltage air conditioning (HVAC) ductwork, electrical distribution networks, washlights, spotlights, battens, winches, cables, and fire systems were hung from the roof structure (the ancillary fixtures). The layout of the primary and secondary trusses in relation to the bays is shown in the figure below.

22. The building was a D-shape. The ends of T1 to T4 and T5 to T8 sat on the concrete box culvert, supported by sliding pot bearings and sliding rocker bearings. The primary and secondary trusses were allowed to move along the bearings when the structure was in place to deal with movement in the roof structure caused by expansion and contraction of its steel members. There was no upward restraint of the primary or secondary trusses where they sat on the sliding pot bearings or the sliding rocker bearings.

23. The intersection of the primary and secondary trusses divided the premises into nine bays that were referred to as Bays 1 to 9 as labelled in the figure above.

24. The structural members of the roof structures in Bays 1, 3, 4-6 and 8 formed 5m squares within each bay (as depicted in Bay 4 in the figure above). The configuration of the structural members in Bays 7 and 9 was different because of the rounded corners of the premises. The configuration of Bay 2 was unique because it had structural members running in an east-west orientation only, with no perpendicular members.

Events prior to 19 March 2016

Review Meetings

26. Lendlease arranged meetings between its employees and Michael Khoury, the General Manager of Hassarati, to review the plan for the proposed demolition of the premises. The purpose of the review meetings was for the senior managers of Lendlease to satisfy themselves that the demolition of the premises, which was high risk work, could be undertaken safely. Review meetings were held on 20 February 2015, 24 June 2015, 12 August 2015, 25 September 2015, 13 October 2015, 6 November 2015, 13 November 2015, 17 November 2015, 7 December 2015, 15 December 2015, 14 January 2016, and 11 February 2016 (the review meetings).

27. A PowerPoint presentation, titled ‘Demolition Methodology Presentation’, was initially prepared by Mr Khoury, to be shown and discussed by the attendees of the review meetings (the Hassarati Demolition Methodology). The updating of this document later became the responsibility of Tim Arnold, a Site Engineer employed by Lendlease and became known as the ‘QCUA Demolition Methodology’. There were a number of iterations of the QCUA Demolition Methodology, starting at Revision A and going up to at least Revision P (with the letters I and J being omitted). There was also a tailored version presented to SafeWork NSW and Peter Trickett of SCP Consulting Pty Ltd (SCP) and there may have been others that were not identified. Mr Trickett was a structural engineer retained by Lendlease to review the demolition methodology. He was a director of SCP.

28. It was the usual practice for the document being presented to be printed and given to the attendees of a review meeting as well as being displayed on a screen during the review meeting.

The first inspection of the premises on 16 March 2015

29. On 16 March 2015, there was a site walk around the premises involving Lendlease, Hassarati and Mr Grasso. At that time, the premises were still being used as an entertainment venue. An inspection took place of the roof structure and the internal box girder structure and there was a discussion of the demolition of the structure without the use of propping. Mr Grasso walked on the arena floor, up the tiered seating and along the suspended catwalk. He went out onto the external surface of the roof. The bearings of the primary and secondary trusses were obscured behind heavy curtains. The arena was in darkness and unlit. The roof structures were painted black.

30. On 30 July 2015, Mr Grasso attended a meeting at Hassarati’s offices to discuss the demolition of the premises. No evidence was given about what occurred or what was said at that meeting.

31. On 12 October 2015, Mr Grasso sent an email to Mr Khoury enquiring if there were any existing structural drawings available for the site.

32. In or about early December 2015, Hassarati provided to GCE an incomplete set of drawings that had been obtained by Lendlease. No ‘as-built’ drawings were available. The structural drawings showed that the primary and secondary trusses had been supported using temporary towers, during the construction of the roof of the premises, which were removed when the roof was completed.

The Review Meeting of 7 December 2015

33. On 7 December 2015, Mr Grasso attended a review meeting.

34. Also present at the 7 December 2015 review meeting were Mr Khoury and a number of employees from Lendlease, namely, Andrew Whitten (Construction Manager), David Patterson (Chief Operating Officer), Robert McDermott (Site Manager) and Stephen Surjan (Operations Manager)..

35. Revision H of the QCUA Demolition Methodology dated 25 October 2015 was presented at the meeting. Revision H was prepared by Mr Arnold and included two diagrams on pages 27 and 28 which depicted shading covering all of bays 1, 6 and 9 and 3, 4, 8 and 9 respectively. Text to the right of the diagram read, “Demolish roof sheeting, purlins and secondary structural beams … using long reach excavator with shear attachment working from ground slab”.

36. The attendees of the meeting who were called, gave limited evidence of what was discussed.

37. Mr Khoury gave evidence referring to the notes he made at the meeting. Mr Khoury gave evidence that the Lendlease representatives required Mr Grasso to inspect the demolition work once every two weeks once it commenced. Mr Khoury gave evidence that there was no discussion of the sequencing of the demolition of the roof structure at the 7 December 2015 meeting. This was supported by the content of Mr Khoury’s notes.

38. Mr Whitten gave evidence that Mr Grasso attended ‘many’ of the other review meetings. Mr Whitten gave evidence that it was always his understanding, from conversations with Mr Khoury and other employees of Lendlease, that the roof structure would be demolished on a bay-by-bay basis by removing all of the roof sheeting, purlins and structural members from within a bay, leaving only the primary and secondary trusses. Mr Whitten accepted in cross-examination that his understanding of the sketches sent by him as part of the approving of the demolition methodology did not come from anything said to him by Mr Grasso. Mr Whitten was taken in his evidence to the notes he made at the meeting. None of those notes related to the demolition sequencing or the extent to which the structural members in each bay would be removed.

39. Mr McDermott did not recall attending the meeting and did not give any evidence as to what was said at that meeting. Mr McDermott also alleged that Mr Grasso had attended other meetings about the demolition but could not specify when those meetings were or what was discussed at them. Mr McDermott’s understanding was all of the structural members in each bay would be removed except for the primary and secondary trusses. Mr McDermott accepted that he had not seen any sketch prepared by Mr Grasso and that he could not explain how Lendlease had incorporated any sketch into the QCUA Demolition Methodology.

40. Mr Arnold did not attend the meeting. Mr Patterson and Mr Surjan were not called to give evidence.

41. Mr Arnold was asked by the prosecutor to compile a summary of the attendees at the various review meetings by reference to emails, calendar invites and minutes of the review meetings. The information collated by Mr Arnold did not support the evidence of Mr Whitten and/or Mr McDermott that Mr Grasso had attended other review meetings. Further, it was an agreed fact that the 7 December 2015 review meeting was the only one attended by Mr Grasso.

42. No questions were put to Mr Grasso in his interview with Inspector Walker on 5 October 2016, referred to in detail at [113] to [125] below, about the 7 December 2015 review meeting.

43. Having reviewed all of the evidence, no witness gave any evidence of anything alleged to have been said by Mr Grasso at the 7 December 2015 review meeting and I am satisfied, on the contemporaneous documents, that the 7 December 2015 review meeting was the only review meeting attended by Mr Grasso and that Mr Whitten’s and Mr McDermott’s evidence to the contrary should not be accepted.

The 14 December 2015 Engineer’s Report and the 14 December 2015 sketch

44. On 14 December 2015, Mr Grasso issued to Hassarati an “Engineers Report Re: Demolition of Entertainment Centre Roof Our Ref: 01360 1” (14 December 2015 Engineers Report), that included:

We have reviewed the limited structural drawings available to the above project and have prepared a sequencing layout to demolish the roof structure based on existing structural drawings.

The demolition sequencing is preliminary at this stage and will be further refined once soft strip out is completed to expose the structural framing system of the roof.

We have prepared the attached colour co-ordinated scheme outlining the demolition process for the bottom chord members of the roof.

Based on the limited structural drawings available for the roof structure to the Entertainment Centre comprises of a three dimensional trusses and beam system with catwalk structures with a framed steel system supporting purlins to create a sloping roof structure.

We stress that this is only a preliminary scheme to ensure that discrete segments of the roof are demolished to ensure that the overall stability of the roof structure is maintained at all times.

45. The 14 December 2015 Engineers Report included a photocopy of a page marked CD3 of the structural drawings (14 December 2015 sketch). Mr Grasso had coloured parts of the 14 December 2015 sketch using 4 different coloured highlighter markers, in the areas of Bays 3 and 4. He wrote on the 14 December 2015 sketch a key indicating the order of removal of the structures.

46. Mr Grasso coloured Bays 3 and 4 in yellow highlighter in the area bordered by the concrete box culvert to the south and west, by T3 and T4 to the east and to the beams identified as P3 to the north in Bay 3 and P6 in Bay 4. The yellow colour delineated the ‘1st removal’. Mr Grasso highlighted beams running from west to east in Bay 3 (not including the beam marked P3 to the north) and two beams running west to east in Bay 4 (being the first and third beam in from the concrete box culvert to the south), with a purple highlighter. The purple colour delineated the ‘2nd removal’. Mr Grasso highlighted in blue all beams running north to south between the concrete box culvert and T1 and T2 in Bay 3 and between T1 and T2 and T3 and T4 in Bay 4. The blue colour delineated the ‘3rd removal’. Mr Grasso highlighted in orange, two beams in Bay 4 running east to west, being the second and fourth beams in from the concrete box culvert to the south. The orange colour delineated the ‘4th removal’.

47. In the 14 December 2015 sketch there was an area 10m wide running west to east to the south of T5 and T6 that was not highlighted at all. This area contained structural members running west to east and north to south, that were also diagonally braced. An available construction of the 14 December 2015 sketch was that by not marking those structural members that Mr Grasso intended that they should not be removed.

48. Mr Khoury gave evidence in chief that he interpreted the 14 December 2015 sketch when he saw it as providing for the removal of all structural members from within each bay. Mr Khoury gave evidence that he had that understanding from the discussions that he had with Lendlease in the review meetings and more generally and because that was his own subjective view. In cross-examination, Mr Khoury agreed that he signed a statement prepared by the defendants’ solicitor after a conference with him and that he realised when he saw the 14 December 2015 sketch on that date, that it did not involve removing all of the structural members in Bays 3 and 4, with the exception of the primary and secondary trusses.

49. The prosecution case on this point, was that Mr Grasso made an error in failing to mark all of the structural members in Bays 3 and 4, because it was the common understanding of Lendlease, Hassarati and GCE that all structural members would be removed from each bay leaving only the primary and secondary trusses in place. In the alternative, the prosecution contended that the documents provided by Mr Grasso were not explicit enough to indicate that the unmarked structural members were to be left in place for structural stability during the course of the demolition. I will return to deal with these factual issues later.

The Hassarati sketch

50. On 17 December 2015, Hassarati sent an email to Lendlease, attaching an updated version of the Hassarati Demolition Methodology. Page 25 of the document included a coloured diagram of the demolition sequence (Hassarati sketch). Mr Khoury gave evidence that he created the Hassarati sketch after receiving the 14 December 2015 Engineer’s Report and the 14 December 2015 sketch. The Hassarati sketch was different to the 14 December 2015 sketch in several respects.

51. First, Mr Khoury superimposed an icon of an excavator onto the sketch. Second, he entirely removed the shading in Bay 3. Third, he only referred to first, second and third cuts, or three sequenced removals. The first cut marked in yellow, referred to the roof sheeting and purlins. The second cut marked in orange, referred to the secondary beams. The third cut marked in green, referred to the primary beams.

52. Mr Khoury shaded the same area of Bay 4 as Mr Grasso shaded on the 14 December 2015 sketch.

53. Mr Khoury did not seek Mr Grasso’s consent before making these changes, nor did he advise Lendlease that he had altered the sketch before providing it to them. Mr Khoury did not inform Lendlease that the demolition sequence that Mr Grasso had specified in the diagram was preliminary. Mr Khoury did not send the 14 December 2015 sketch to Lendlease.

54. Mr Khoury gave evidence that his understanding that all of the structural members were to be removed from each bay was not altered by his preparation of the Hassarati sketch.

Events following the provision of the Hassarati sketch to Lendlease

55. The prosecution case was that Mr Khoury provided the Hassarati sketch to Mr Grasso before sending it to Lendlease. I will return to this factual issue later.

56. On 19 December 2015 GCE issued a tax invoice to Hassarati. This tax invoice made no reference to the Hassarati sketch.

57. On or about 23 December 2015, Hassarati prepared a “Work Health and Safety (WHS) Management Plan” (WHSMP). Hassarati did not provide Mr Grasso with a copy of the WHSMP.

58. On 29 December 2015 GCE issued a tax invoice to Hassarati. This tax invoice included an entry, “Meet Michael Khoury on site, prepare final review of demolition sequence methodology for Lend Lease for the roof and concrete box girder section demolition”.

59. On or about 31 December 2015 possession of the premises was handed over to Lendlease. Scaffolding and hoardings were erected around the outside of the premises in preparation for the demolition. The premises were secured and locked. Ultimately, the keys to enter the site were given to Mark Ghabache, the site supervisor employed by Hassarati. Mr Ghabache had control of who was permitted to enter the premises during the demolition work.

60. On 7 January 2016, Hassarati prepared a Safe Work Method Statement (Hassarati SWMS). It included Job Description 8, ‘Demolish roof sheeting, purlins and secondary beams using 70t long reach excavator with shear attachment.’ Hassarati did not provide Mr Grasso with a copy of the Hassarati SWMS.

61. GCE’s Tax Invoices do not record that Mr Grasso completed, prior to the incident, any engineering investigation involving performing engineering analyses and/or undertaking engineering calculations.

The 11 February 2016 Engineer’s Certificate

62. Lendlease requested an Engineer’s Certificate from Hassarati to confirm the stability and integrity of the roof structure during demolition.

63. On 11 February 2016 at 9.56am and 10.06am respectively, Mr Khoury emailed Mr Grasso the Hassarati sketch and a request for advice and information in the following terms:

For the sequence of the roof demolition (the coloured plan I just sent, we want to confirm that that sequence for each bay is ok for the structural integrity of the roof and that it doesn’t matter in what order each bay is demolished.

64. The coloured plan was the Hassarati sketch.

65. On 11 February 2016 at 11.03am, Mr Grasso sent to Mr Khoury by email the “Engineers Certificate Re: Entertainment Centre – Roof Demolition Our Ref: 01360-5” (11 February 2016 Engineers Certificate) signed by him. The 11 February 2016 Engineers Certificate represented:

Further to our previous Engineers Certificate No. 01360-1 dated 14 December 2015 any bay of the roof structure can be demolished in any order in the sequence shown on the attached sketch No. 01360-SK1 dated 11 February 2016 and still maintain the integrity of the roof.

66. The attached sketch No. 01360-SK1 (11 February 2016 sketch) was a copy of the Hassarati sketch, to which Mr Grasso had affixed a GCE stamp and marked on it in handwriting the words ‘Entertainment Centre Roof Demolition Sequencing DWG no. 01360-SK1’.

67. On 11 February 2016 at 11.36am, Mr Khoury emailed the 11 February 2016 Engineers Certificate, which attached the 11 February 2016 sketch, to a number of employees of Lendlease.

The creation of Revision O of the QCUA Demolition Methodology

68. On 12 February 2016, Mr Arnold prepared Revision O of the QCUA Demolition Methodology (Revision O). In Revision O Mr Arnold included a digital version of the 11 February 2016 sketch that was created by him (the Arnold sketch).

69. The Arnold sketch extended the shading in Bay 4 to the whole bay in yellow and marked the primary beams with green lines and the secondary beams with orange lines using a computer. The key that had been handwritten on the document by Mr Khoury was typed onto the sketch. The Arnold sketch appeared in Revision O next to a copy of the 11 February 2016 Engineer’s Report. Mr Arnold also typed other notes that appeared on the face of the Engineer’s Report.

70. The Arnold sketch differed from the 14 December 2015 sketch, the Hassarati sketch and the 11 February 2016 sketch, by marking for removal all of the structural members within a bay except for the primary and secondary trusses.

71. Mr Arnold gave evidence that he prepared the Arnold sketch on the basis of his understanding that all of the structural members would be removed from a bay, except for the primary and secondary trusses. Mr Arnold gave evidence that he gained that understanding from his discussions with employees of Lendlease and with Mr Khoury.

72. The Arnold sketch appeared in every later revision of the QCUA Demolition Methodology.

73. Mr Arnold emailed Revision O to Mr Khoury on 20 February 2016. Mr Khoury gave evidence that he recognised the sketch contained in Revision O was different to the 11 February 2016 sketch but did not advise Lendlease of this.

74. There was no evidence that Revision O or any later revision of the QCUA Demolition Methodology was provided to Mr Grasso.

Approval of the Demolition Methodology

75. At the final review meeting that took place on or about 15 February 2016, Revision P of the QCUA Demolition Methodology was presented. The methodology was approved allowing work to commence on the demolition.

76. Revision P of the QCUA Demolition Methodology was provided to Mr Ghabache as his instructions on the steps to be undertaken in the demolition of the premises. The Arnold sketch was reproduced at page 18 of Revision P. Mr Khoury made a colour copy of the Arnold sketch and had it laminated for use on site. Mr Khoury provided the laminated copy to Mr Ghabache with the other documentation to be kept by him on site.

77. At some time prior to the commencement of the demolition of the roof structure, Mr Ghabache instructed workers to use elevated work platforms to spray fluorescent paint on the primary and secondary trusses to indicate that they were not to be removed.

Instruction of the Rosenlund workers

78. On 4 March 2016 the excavator, Mr Hayward and Mr McClutchie arrived from Queensland. Mr Hayward had experience with the operation of the excavator for about 6 years prior to the incident. Mr McClutchie had been the only operator of the excavator during that period.

79. Mr Ghabache showed the laminated copy of the Arnold sketch and Revision P to Mr Hayward and Mr McClutchie when instructing them as to the work to be undertaken, during the course of their induction to the site.

80. Mr Hayward did not like the demolition methodology because it involved bringing down materials on top of the excavator and in the area where he and Mr McClutchie would be. In his opinion, the roof structure should have been removed from above using cranes, before demolishing the concrete arena. Mr Hayward raised those concerns with Mr Arnold, who assured him that the option they were pursuing had engineering approval. Mr McClutchie gave evidence that he shared the same concerns.

81. On 4 March 2016, fitters from Rosenlund put the boom of the excavator together with the assistance of a crane. On 5 March 2016 the assembly of the boom was completed. Initially the fitters assembled two sections of the boom but that made it too long, with the boom hitting the bottom of the trusses before it could get to the height of the roof, so the length of the boom was reduced by removing one of the sections. According to the contemporaneous record made by Mr Hayward some demolition of the first bay was undertaken.

The commencement of demolition work

82. On 7 March 2016, the demolition work continued. This involved the operation of the excavator by Mr McClutchie under the supervision and guidance of Mr Hayward. There were occasions when Mr McClutchie’s vision was obscured by the fall protection system on the excavator or because of the angle on which he approached the roof and he was on those occasions dependent on what Mr Hayward could see from outside of the excavator cabin.

83. The excavator was positioned on the arena floor in an area which was not underneath where the demolition was taking place. The excavator boom could be extended upwards and forwards of the main cabin for a distance of about 20m. The excavator used two different attachments to demolish the roof structure; a pulveriser that was used to grab and pull things but could also cut purlins and ancillary fixtures up to 300mm wide with a cutter positioned in its throat and shears that were used to cut the primary and secondary beams that were in excess of 300mm wide. The work had to be stopped to change the attachments on the boom.

84. The order in which the bays of the roof structure were demolished was determined on site by Mr Ghabache and Mr Hayward. Both Mr Ghabache and Mr Hayward held unrestricted demolition supervisor qualifications. Mr Ghabache had no experience with the long reach excavator. A tool box talk was conducted by Mr Ghabache each day before work commenced on the demolition of the roof structure.

85. Initially, Mr Ghabache decided to start with Bay 3. Mr Ghabache gave evidence that the excavator commenced in Bay 3 by trying to remove a structural member to get access to the roof. In doing so more of the structure started to come down than was expected. The process was stopped at that point and the excavator moved to Bay 2.

86. Mr Ghabache chose Bay 2 to try next because it had the least clutter and it seemed to be the easiest place to make a hole in the roof. The demolition commenced by removing the ancillary fixtures from under Bay 2. Mr Ghabache gave evidence that a structural member was removed from Bay 2 to open up access to the roof from the underneath. After that was done roof sheeting and purlins were removed over an area, before the structural members underneath were cut and allowed to fall down to the arena floor. The demolition of each bay proceeded in this fashion, by demolishing all of the roof structure in a 5-7m width, before demolishing another 5-7m width.

87. Mr Ghabache gave evidence that the configuration of the excavator arm necessitated the demolition occurring in this way because there was insufficient space between the structural members of the bay to allow all of the roof sheets and purlins to be removed first. The extension of the arm on the excavator only allowed it to reach about 7m in front of where it protruded through the roof, requiring the removal of primary and secondary beams in sections before the arm could be extended through the roof again.

88. Mr Ghabache agreed in cross-examination that this method of demolishing the roof structure within a bay was demonstrated in a number of photographs of different bays taken during the course of the demolition. Mr Ghabache gave evidence that this methodology was followed in the demolition of each of the bays.

89. Mr Khoury gave evidence that his interpretation of the demolition sequence contained in the demolition methodology was that the roof sheeting and purlins would be removed first in any section of a bay being demolished, because the primary and secondary beams could not be removed first as that would result in the roof sheets and purlins coming down at the same time as they were being supported by the primary and secondary beams.

90. Mr Hayward’s evidence was that Mr McClutchie undertook the demolition in accordance with the sequence provided for in the documents. His recollection was that all of the roof sheeting and purlins were removed from a bay before the secondary beams and then the primary beams were cut. Mr Hayward agreed in cross-examination that aerial photographs of Bay 7, Bay 8 and Bay 9 (Exhibits 24, 25 and 26) appeared to contradict his evidence. Mr Hayward stated that Bays 7 and 9 may have been approached in sections because they were larger.

91. Mr McClutchie gave evidence that the demolition proceeded in accordance with the documented sequence. Roof sheeting and purlins were removed first before the secondary beams and then the primary beams were cut. Mr McClutchie gave evidence that Bays 7 and 9 were done in sections because they were much larger. Mr McClutchie gave evidence that after the demolition of Bay 2 the roof sheeting of the other bays could be reached to be removed by moving the boom over the top of the bay through the hole created by removal of the previous bay. Mr McClutchie believed that the sagging of the roof sheeting depicted in Exhibit 25 could have been the result of removing the purlins without removing the structural members.

92. On 7 March 2016, the roof structure in Bay 2 was demolished, with the exception of one intermediate truss running in an east- west direction.

Mr Grasso’s site inspection of 8 March 2016

93. On 8 March 2016, Mr Grasso attended the premises to conduct an inspection. All of the roof structure in Bay 2, with the exception of one intermediate truss running in an east-west orientation, had been removed.

94. On 9 March 2016, Mr Grasso sent by email to Mr Khoury a revised Engineers Report signed by him. [2] Mr Grasso issued the “Engineers Report Re: Demolition of Entertainment Centre Box Girder Structure Our Ref: 01360-9” (9 March 2016 Engineers Report) and represented:

We also undertook an inspection of the roof structure now that the first bay of the roof structure has been removed in accordance with the approved methodology. We confirm that demolition of the roof structure is safe and is to proceed in accordance to the approved methodology.

Removal of the roof structure up to the date of the incident

2. An Engineer’s report sent 8 March 2016 was replaced by the revised report.

95. Mr Hayward believed that the amount of ancillary fixtures in Bay 5 would be time consuming to remove and it would therefore be the most difficult bay to demolish. Accordingly, he thought it was best left until the end, after other less difficult bays had been demolished. Mr Hayward understood that this would not matter because he was told by Mr Ghabache that any bay could be demolished in any order and because by removing the other bays there would be less weight on the primary and secondary trusses when it came time to demolish Bay 5.

96. Mr Hayward gave evidence that after Bay 2 was demolished, the next bay to be demolished was in part selected by where the excavator could be positioned, having regard to the debris created by demolishing the previous bay and whether the other Hassarati workers had cleaned up the area.

97. Both Mr Ghabache and Mr Hayward described Mr McClutchie as a very skilled and careful operator of the excavator. Mr Hayward gave evidence that he did not observe the boom or attachment of the excavator come into contact with the primary or secondary trusses during the course of the demolition. Mr McClutchie also gave evidence that he believed that during the course of the demolition that the boom or attachment to the excavator had not come into contact with the primary or secondary trusses.

95. Later in the day on 8 March 2016 the roof structure in Bay 3 was demolished.

96. On 9 March 2016 the roof structure in Bay 1 was demolished.

97. On 10 March 2016 the roof structure in Bay 6 was demolished.

98. Between 12 March 2016 and 14 March 2016 the roof structure in Bay 7 was demolished.

99. On a number of occasions during the demolition, steel members being demolished fell onto the boom of the excavator and caused damage to the hydraulic hoses and fittings, which had to be repaired by contractors.

100. On 16 March 2016 the roof structure in Bay 8 was demolished.

101. Between 17 March 2016 and 18 March 2016 the roof structure in Bay 9 was demolished.

102. All members and materials had been removed from Bays 2, 3, 1, 6, 7, 8 and 9 by 19 March 2016, exposing the primary and secondary trusses. The roof structure and ancillary fixtures remained in Bays 5 and 4.

103. Mr Grasso was not asked to, and did not attend at the site, at any time between 8 March 2016 and the time of the unplanned collapse on 19 March 2016.

The incident on 19 March 2016

107. Between about 9.56am and 10.56am on Saturday 19 March 2016, Mr McClutchie was operating the excavator to remove the ancillary fixtures from Bay 5. The excavator was positioned on the arena floor under a bay that had already been demolished. The excavator arm extended about 20m horizontally from the cabin of the excavator. At the time of the incident, air conditioning ducts held up by wire were being pulled down to the arena floor.

108. Mr Hayward was acting as a spotter. He was directing Mr McClutchie what to cut and/or grab by two-way radio. Mr Hayward and Mr Ghabache were located in an entrance to the arena floor, underneath the arena seating structure, in view of the excavator.

109. The remaining roof structure, including T1 to T8, the roof members in Bays 4 and 5 and the ancillary fixtures, collapsed suddenly and without warning while the excavator was pulling down the air conditioning duct.

110. Various objects came to rest on the excavator, the arena floor and the arena seating structure. The steel trusses that fell onto the excavator partially crushed the excavator cabin. Mr McClutchie had his hands on the levers and did not have time to move.

111. Mr Ghabache and Mr Hayward ran up to Mr McClutchie to make sure he was all right. They told Mr McClutchie to break the glass because the door of the excavator would not open. Mr McClutchie kicked out the windscreen of the excavator and climbed out.

112. No person was injured arising from the unplanned collapse of the remaining roof structure. The primary trusses detached from their supports at the time of the collapse. The stability of the collapsed structure could not be determined.

Events after 19 March 2016

113. Post-incident, removing the collapsed roof structure involved cutting the steel trusses in strategic locations for them to settle or fall to the arena floor. When the primary and secondary trusses were cut and settled the excavator was ‘written-off’.

Mr Grasso’s Record of Interview

114. On 5 October 2016 Inspector Walker conducted an electronically recorded interview with Mr Grasso (interview). A transcript of the interview and the audio recording of it were tendered against GCE only.

115. Mr Grasso told Inspector Walker that he was a qualified structural engineer who operated as a sole trader through GCE. He was aware of the content of the Demolition Work Code of Practice (DW Code) and the AS2061 Demolition of Structures (AS 2061).

116. Mr Grasso told Inspector Walker that GCE was engaged by Hassarati in about June or July 2015. Mr Khoury telephoned Mr Grasso and asked to meet him on site to discuss the demolition of the premises. Mr Grasso believed that the Scope of Works involved him assisting by undertaking engineering calculations and providing structural engineering advice on the demolition. Hassarati did not enter into a formal contract with GCE. GCE did not assist Hassarati with its tender for the demolition work. Mr Grasso told Inspector Walker that GCE’s advice was contained in formal certificates that noted what he had been required to do. The GCE file had been sent to SafeWork NSW prior to the interview taking place.

117. Mr Grasso told Inspector Walker that he discussed the possibility of using tower crane supports to the intersection of the primary and second trusses when he had discussions with Metropolitan Demolitions, who consulted Mr Grasso about the work during the tender period. It was their intention to dismantle the roof from above. In contrast, Hassarati intended to use the excavator to shear the roof members from underneath. GCE had been provided with an incomplete set of structural drawings for the premises and Mr Grasso could not tell Inspector Walker precisely how the roof had been constructed.

118. In reviewing the drawings provided, Mr Grasso noted that the primary and secondary trusses, as continuous members, could span the full distance and support the roof structure. On the presumption that the roof structure was being dismantled bay-by-bay, thereby removing load from the roof structure, Mr Grasso opined that the integrity of the primary and secondary trusses could be maintained. Mr Grasso told Inspector Walker that the minor trusses provided some restraint for the top chord of the primary and second trusses, by reducing the effective length for restraint of the top chord of the primary trusses. Mr Grasso also believed that the construction of the primary and secondary trusses, as twins, strengthened them in the span between the supporting points and the intersection of the primary and secondary trusses. The primary and secondary beams supported the roof sheeting and the weight of the ancillary fixtures that hung from the roof. Mr Grasso based those opinions on his experience and on the assumption that a systematic demolition of the roof structure would remove weight off the roof structure. He believed that whilst this would remove support from one side of the primary and secondary trusses that it would also take load off the panel (bay). This had the effect of taking weight off the primary and secondary trusses prior to releasing the secondary and primary steel beams. Mr Grasso believed the primary and secondary trusses would still function to support the remaining roof structure as weight was removed from them. Mr Grasso opined that this was demonstrated by the fact that seven bays of the nine were dismantled prior to the unexpected collapse.

119. Mr Grasso was not asked to undertake engineering calculations or provide an engineering investigation report. Mr Grasso did not undertake engineering calculations, because he considered the restraint still in place as the weight of the roof structure came off bay-by-bay as sufficient. Mr Grasso relied on his experience and visual inspection of the roof structure rather than undertaking engineering calculations or other analysis.

120. Mr Grasso was told that there were no funds to provide for temporary propping of the primary and secondary trusses during the course of demolition and it was Hassarati’s intention to dismantle the roof from underneath using the excavator. Mr Grasso was comfortable that the roof structure would be able to support itself as it was being de-loaded and dismantled. Mr Grasso thought that the use of temporary supports during the demolition process may have been reasonably practicable depending upon the method used to demolish the roof structure.

121. Inspector Walker then referred Mr Grasso to the 14 December 2015 sketch noting that there were some structural elements of the roof structure that were not marked for removal in the sketches indicated by Mr Grasso. Mr Grasso was then asked why those structural elements were not included in the demolition sequence. At this point in time, my attention was drawn to a pause on the audio recording that lasted for approximately 60 seconds. There appeared to be some mumbling on the audio recording at this time and some turning of pages. I note that the copy of the sketch shown to Mr Grasso at this time was not a good copy of the document, as some of the colours had not been reproduced on the colour photocopy. Mr Grasso then answered “I’m not sure”.

122. Mr Grasso was then asked if that omission was intentional. He answered, “it would have been because that’s got in-plan bracing to the primary trusses”. Mr Grasso continued to say that it was his intention that those elements would have been demolished at a later time, noting that the 14 December 2015 sketch was only a preliminary sequencing, subject to further investigations after soft stripping had taken place. Mr Grasso was then asked if it was intentional that this document was not an indicative method for all bays, because it referred only to parts of Bays 3 and 4. Mr Grasso responded that it was only a preliminary document until further investigations could be undertaken. Mr Grasso said that the structural drawings were not that clear and accordingly, this sequence was marked as preliminary until further investigations could be undertaken. Mr Grasso also believed that this sequencing would be further refined after subsequent site inspections. Mr Grasso told Inspector Walker that his intention was that the primary beams situated in between the primary and secondary trusses would be the last to be removed.

123. Mr Grasso was then shown the 11 February 2016 Engineer’s Certificate and the 11 February 2016 sketch. Inspector Walker again noted that only part of Bay 4 in this sketch had been highlighted for removal. Mr Grasso accepted that was a correct statement of the position. Mr Grasso said that the 11 February 2016 sketch was a sequencing sent to him by Mr Khoury with a request that he review it, which he did by providing the 11 February 2016 sketch. Mr Grasso was asked if he considered that Bays 5 and 2 had a different structure to the other bays. Mr Grasso stated that he had not considered that. Inspector Walker suggested to Mr Grasso that the secondary beams not highlighted in the 11 February 2016 sketch were not included in the approved demolition. Mr Grasso accepted that statement.

124. Mr Grasso told Inspector Walker that he would have assumed that the weight in the centre of the structure (Bay 5) would have been removed first before the other panels were removed. Mr Grasso told Inspector Walker that he communicated that to Hassarati by the approval of the SafeWork Method Statements if that had been done. Mr Grasso told Inspector Walker that he did not think that the reduction in the demolition methodology of four steps to three steps made any practical difference.

125. Mr Grasso agreed that he undertook a site inspection on 8 March 2016 and issued a further Engineer’s Certificate at that time. Mr Grasso did not recall any details of the site visit. He accepted that the photograph of the demolition as at 8 March 2016 shown to him was accurate. Mr Grasso agreed that in looking at that photograph that some beams had been taken out in the demolition process that were not shown to be removed in the Engineer’s Certificates, being the members that were closest to trusses T1 and T2 in Bay 2. This was an acceptance of the proposition put to him by Inspector Walker. It should be noted that the proposition did not correlate to the structural drawings of Bay 2. In other words, the premise of the question is not proved by the contemporaneous documentation.

126. Mr Grasso was then shown later photographs of the demolition process. Mr Grasso agreed that the demolition process had taken out structural members not marked for removal on the Engineer’s Certificates. Mr Grasso did not recall discussing with anyone from Hassarati at any time about retaining those structural members. Mr Grasso said that any information he provided to Hassarati about those members was in the documents.

Expert evidence

127. The prosecution qualified Professor Kim Rasmussen and Dr Mike Bambach from the Centre for Advanced Structural Engineering (CASE) at the University of Sydney (the Experts). Both of the Experts are eminently qualified academics. It should be noted that neither of the Experts had recent or considerable experience as a practising structural engineer.

128. The Experts were asked to determine the cause of the collapse of the remaining roof structure at the Premises and to answer a number of specific questions. To undertake those tasks, Dr Bambach, created a structural model using commercial structural analysis software, ‘Strand 7’. This involved entering the details of the structural members supplied in the engineering drawings that were available, into the software. Assumptions were then made as to the mass of other non-structural elements such as purlins, roof sheeting, the ceiling and insulation materials. These assumptions were made in accordance with engineering practice. A further assumption was made as to the mass of the ancillary fixtures that were identified from various photographs. The Experts assumed an additional gravity load of 0.25kPa or 0.5kPa.

129. Assumptions were made in respect of wind speed. The wind speed was not recorded at the time of the collapse and accordingly the wind speeds recorded at Sydney Harbour on the day of the incident, as published by the Bureau of Meteorology (BOM), were used. These assumed a 9am wind speed of 24 kph and a maximum gust speed of 56 kph.

130. A further assumption was made that it was unlikely that the structure, as it existed on the day of the incident, had perfect geometry. It was assumed that the 42.53 metre spans of the primary trusses T5 – T8 east of Bay 5 were not completely straight because the structure had been in service for some years, there were probably imperfections introduced during fabrication and erection and there had been some demolition of adjacent bays resulting in the removal of lateral restraint. The extent of the imperfections were unknown so three different values were used of zero, span/300 (142mm) and span/100 (425mm).

131. The adoption of these three assumptions gave rise to a range of likely scenarios within the model.

132. In order to consider the cause of the collapse, the structure as it existed at the time of the collapse, was modelled. In order to answer the other questions, the entire roof structure prior to the commencement of demolition was modelled after which the bays of the roof were sequentially removed in the model and analyses undertaken at each step in the process to identify an alternative sequence of demolition that did not result in a risk of collapse.

133. At the time of the collapse, T5 and T6 were laterally unrestrained over a length of 42.53 metres (east of Bay 5). This left these trusses susceptible to the instability mode of lateral buckling. In addition, the end bearings for these trusses did not contain any upward restraint. The combination of no lateral restraint and end bearings with no upward restraint, resulted in an instability mode in which the trusses laterally buckled while twisting over and off their supports at the eastern end precipitating the failure of the roof.

134. Theoretically, a load factor of 1.0 predicts that a structure will collapse. The modelling results for the structure, as it existed immediately before the collapse, produced load factors of between 0.91 and 1.19 in the structural model. This predicted that buckling would occur at a load of between 9% less than and 19% greater than the load that was applied to the structure, depending on the values accepted for the assumed gravity load, wind speed and the magnitude of imperfection. T5 and T6 were predicted to buckle prior to T7 and T8 because the loads from Bays 4 and 5, which were still weight bearing, were asymmetric, causing higher loads on T5 and T6.

135. The lateral buckling failure of T5 and T6 resulted in a rapid loss of their stiffness and load carrying capacity, which led to the loads being carried by these trusses to be re-distributed to the remaining primary and secondary trusses. The increase in load on T7 and T8 led to lateral buckling failure in these trusses identical to that in T5 and T6 with subsequent separation from their eastern supports. The load factor for this buckling load was 28% less than T5 and T6, which predicts that once T5 and T6 buckled, T7 and T8 would have subsequently immediately buckled. T7 and T8 were identical to T5 and T6 with regards to their lack of lateral restraint and lack of upward end restraint.

136. This left T1 to T4 to carry the entire load including the self-weight of trusses T5 to T8. This resulted in a combination of vertical sag and twisting. The Experts predicted that following the separation of trusses T5 to T8 from their eastern supports, the northern spans of trusses T1 to T4 buckled while their southern ends displaced in plane and separated from their southern supports resulting in the roof structure falling to the ground.

137. The Experts noted that there were fractures to the bottom chords of T5 and T6 identified in post-collapse inspections, located on either side of their intersection with T3 and T4. The Experts opined that based on the modelling, the roof collapse was precipitated by lateral buckling of T5 and T6. Lateral buckling results in the rapid loss of stiffness and load carrying capacity which led to the failure of T5 and T6. It is possible that the fractures occurred either immediately following buckling of T5 and T6 as a result of twisting stressors or upon impact of the roof structure with the ground. The Experts opined that the fractures were not involved in precipitating the roof collapse.

138. The Experts then went on to model the actual demolition sequence of the roof structure. This was done by deleting all of the structural members from within a bay on a bay-by-by basis in accordance with the actual dismantling disorder, which were Bays 2, 3, 1, 6, 7, 8 and 9. At the time when Bays 4, 5 and 9 remained, the model indicated that the roof structure became unstable and was susceptible to lateral buckling of T5 to T8. The results of this modelling is summarised in Figure 7 of the Experts’ February 2017 report which is reproduced below.

139. These figures were calculated using the highest assumptions for gravity, wind speed and imperfections to simulate the worst case scenario. The Experts stated that it is standard engineering practice to assess the worst case loading situation. If it can be demonstrated that the structure can resist the maximum expected loads, then it follows that it can resist all other expected load magnitudes without further analysis.

140. The Experts then modelled one alternate sequence of demolition being dismantling the bays in the order of 1 to 6, 7, 9 and 8. The result of this analysis was identified in the Experts’ February 2017 report in Figure 8 which is reproduced below.

141. This dismantling sequence was identified by the Experts using engineering judgment. The Experts opined that load should be removed from the centre of the truss spans first and the longer spans should have their lateral bracing removed last. This judgment led to the selection of the sequence 1 to 6, 7, 9 and 8. The sequence led to a load factor for failure of 1.3, assuming the maximum load values. Other combinations of dismantling sequences were not analysed.

142. The Experts stated that the computer modelling predicts a load factor. However, a structural engineer must take into account any inherent uncertainties not considered in the computer modelling to establish the risk of failure including uncertainties in load values, the materials used, connections and workmanship. The Australian Standards provide statistical methods which the engineering profession agrees are appropriate to define an acceptable risk. This generally involves increasing the load values whilst decreasing the strength values according to statistically derived factors. The relevant factors for the roof structure were 1.35 for the gravity load and 0.9 for strength, resulting in a load factor of 1.35 x 0.9 = 1.5 (AS/NZS 1170.0). Accordingly a load factor of 1.5 for failure would be considered an acceptable level by the structural engineering profession. A load factor of 1.0 would be considered an unacceptable risk. The degree of risk corresponding to the two values between 1.0 and 1.5 would be a decision made by the structural engineer on a case-by-case basis, according to their engineering judgment. The Experts opined that it would be appropriate to consider the consequences of collapse, being low in the present case because the building was not occupied by persons or property, except for the demolition workers and equipment. In this case where maximum loads were considered in the analysis, there was a measure of conservatism in the load values. Thus, the Experts considered that values between 1.0 and 1.25 would be high risk and in most situations were unlikely to be accepted by a structural engineer, and values between 1.25 and 1.5 would be low risk with values below 1.25, an unacceptable risk and values above 1.5, an acceptable risk. Accordingly, the load factor of 1.19 arrived at by the structural model, when assuming the minimum assumed values, would represent a high risk of collapse.

127. Professor Rasmussen opined that a structural engineer should have been concerned about the weight of the ancillary fixtures in Bay 5, and that those fixtures should have been removed first if it was safe from a buckling perspective to do so. The weight of the ancillary structures on Bay 5 placed a significant load on T5 and T6 that were not laterally restrained at the time of the collapse. This should have prompted consideration of methods to reduce the loads on the structure. This could potentially have been achieved by temporarily jacking up the primary and secondary trusses at the intersection points. This would have reduced the loads and the propensity for lateral buckling.

128. Professor Rasmussen gave evidence that the roof was a large and unusual structure that needed to be subjected to a finite element buckling analysis. This could only be achieved through computer modelling and ‘hand’ calculations which were insufficient for this purpose.

129. Dr Bambach gave evidence that the computer modelling process took him 74 hours to complete. Of this time, 70% was spent creating the model, 20% calculating and inputting the load magnitudes and 10% interpreting and analysing the results.

130. Dr Bambach also opined that the weight left in Bays 4 and 5, towards the end of the demolition process was problematic and could lead to buckling of T5 to T8.

131. In cross-examination, Professor Rasmussen was challenged as to the assumed values for wind speed, load and imperfections. It was suggested that the upper end of these figures was unreasonable, for various reasons, and accordingly resulted in artificially low load factors. In my view, that cross-examination misconstrued the purpose of making those assumptions, for the following reasons. First, the upper limit of the assumed values gives the ‘worst case scenario’, meaning that if the predicted load factor is acceptable at those levels, then no further analysis is required. Second, the predicted values are theoretical. In the present case, the structure in fact, collapsed, meaning that the load factor was less than or equal to 1.0. Accordingly, if the predicted load factor was above 1.0, then it was wrong and the inputs into the analysis were also wrong by being too conservative. Third, the Experts had to make some assumptions for these values, in circumstances where the precise values were unknown. The Experts adopted a range of values to provide for a range of results. Fourth, the defendants did not challenge in cross-examination the Experts’ interpretation of the AS 1170.0. It follows that even if the highest load factor predicted by the model of 1.19 (that adopts the lowest value for each variable) was correct, the risk posed was still an unacceptable risk.

132. The Experts were not asked to model the GCE advice alternative. The Experts agreed that providing additional lateral support for the primary and secondary trusses would increase the buckling load factor, thereby lessening the chance of collapse.

Factual issues and findings

What was the approved methodology?

151. It is useful to recap GCE’s advice and to understand what it objectively conveyed before referring to the prosecution arguments.

152. The advice given by GCE on 14 December 2015 comprised of the 14 December 2015 Engineers Certificate and the 14 December 2015 sketch, which is described at [43]-[46] above.

153. The approved methodology at this time, objectively contained four elements:

1. removal of some, but not all, of the structural members of Bays 3 and 4;

2. removal of those structural members in a particular order;

3. that the demolition of Bays 3 and 4 was the first stage in a staged scheme of demolition; and

4. that the scheme was only preliminary to ensure that discrete segments of the roof were removed to ensure overall stability of the roof was maintained.

154. The 14 December 2015 documents were sent by GCE to Hassarati. They were not sent by Hassarati to Lendlease. Hassarati did not inform Lendlease that the scheme was preliminary only.

155. On 11 February 2016 Mr Khoury sent the Hassarati sketch to Mr Grasso by email, which is described at [49]-[51] above. Mr Khoury sought advice from GCE as to whether the demolition sequence was acceptable for each bay for the structural integrity of the roof and that the bays could be demolished in any order.

156. The area marked on Bay 4 by Mr Khoury was identical to the area that had been marked by Mr Grasso on the 14 December 2015 sketch. The number of steps in the removal sequence was reduced from four to three.

157. On 11 February 2016, Mr Grasso adopted the Hassarati sketch (the 11 February 2016 sketch) and sent it with the 11 February 2016 Engineer’s Certificate by email back to Mr Khoury.

158. At this point, the approved methodology was changed as a result of contact between Hassarati and Mr Grasso on behalf of GCE and was now objectively comprised of three elements:

1. removal of some, but not all, of the structural members in Bay 4, which was representative for each bay;

2. removal of those structural members in a particular order; and

3. the demolition of any bay of the roof structure could take place in that sequence, in any order, and still maintain the integrity of the roof.

159. Later on 11 February 2016, Mr Khoury sent the 11 February 2016 sketch to Lendlease.

160. Mr Arnold then created a digital version of the 11 February sketch (the Arnold sketch), by extending the shading in Bay 4 to cover the whole bay in yellow and marking the primary beams with green lines and the secondary beams with orange lines using a computer. The key that had been set out by Mr Khoury, was typewritten on the document. The Arnold sketch was incorporated into Revision O of the QCUA Demolition Methodology dated 12 February 2016, alongside a copy of the 11 February 2016 Engineer’s Report. Mr Arnold also typed other notes relating to the demolition of the roof structure onto the copy of the Engineer’s Certificate.

161. Mr Arnold prepared the Arnold sketch based on his understanding of the demolition methodology that all of the structural members from each bay would be removed, leaving only the primary and secondary trusses. Mr Arnold gained that understanding from his participation in discussions between representatives of Lendlease and Hassarati. The Arnold sketch appeared in each subsequent revision of the QCUA Demolition Methodology.

162. The Arnold sketch had the effect of changing the approved methodology to involve only two elements:

1. removal of all structural members from within a bay in a particular sequence; and

2. the demolition of any bay of the roof structure could take place in that sequence, in any order, and still maintain the integrity of the roof.

The prosecution arguments

163. The prosecution contended that Mr Grasso made a mistake when he prepared the 14 December 2015 sketch, in that he should have shaded the whole of Bays 3 and 4, thereby indicating the removal of all of the structural members in each bay except for the primary and secondary trusses, because he knew that was how Hassarati and Lendlease intended the demolition to take place and accordingly, the demolition of the roof structure took place in compliance with GCE’s advice.

164. The fact that Mr Grasso made an error is an essential fact in this reasoning process, which was intended to establish guilt, and accordingly the prosecution must establish that fact beyond reasonable doubt: Shepherd v The Queen (1990) 170 CLR 573 at 579-580 per Dawson J (Mason CJ, Toohey and Gaudron JJ agreeing).

165. The prosecution submitted that Mr Grasso’s error was apparent from the following matters:

1. Mr Grasso knew from attending the review meeting on 7 December 2015, that it was the understanding of Lendlease and Hassarati that the whole of the roof structure would be removed from each bay leaving only the primary and secondary trusses.

2. Mr Grasso knew that the demolition of the primary and secondary trusses by oxy-acetylene cutting could not take place until all of the structural members from each bay had been removed. If Mr Grasso intended to leave some structural members in each or some bays that the demolition methodology had not provided for, when and/or how would those structural members be removed.

3. A related argument to (2) was that Mr Grasso’s proposed sequence was not readily apparent for Bays 2, 5, 7 and 9 because those bays had a different structural design to that of Bays 1, 3, 4, 6 and 8.

4. GCE sent a tax invoice dated 29 December 2015 that included an entry to the effect that there was a meeting between Mr Khoury and Mr Grasso to ‘review the final demolition methodology’. The prosecution submitted that I should infer that Mr Grasso settled the Hassarati Demolition Methodology sent to Lendlease by email on 17 December 2015, which included the Hassarati sketch.

5. Mr Grasso gave inconsistent versions on the topic during the course of his interview with Inspector Walker.

Did Mr Grasso make an error in preparing the 14 December 2015 sketch?

166. Revision H included 2 diagrams with all of the bays shaded, next to a reference to the removal of the roof sheeting, purlins and secondary beams. There was no evidence that the removal of all structural members from a bay was discussed at the review meeting on 7 December 2015. It should be noted that there had been 8 review meetings prior to the one on 7 December 2015. The effect of the evidence of Mr Whitten, Mr McDermott and Mr Khoury was that they always had understood from their discussions between each other, that all of the structural members would be removed from a bay. This does not establish that Mr Grasso knew of that understanding.

167. By itself, the depiction in the diagrams in Revision H is insufficient to satisfy me that Mr Grasso actually knew or should have known that it was the intention of Lendlease and Hassarati to remove all of the structural members from each bay.

168. There is no direct evidence of anything that was said by Mr Grasso in the review meeting of 7 December 2015.

169. There was no direct evidence of what Mr Grasso’s understanding was after the review meeting on 7 December 2015. He was not asked any questions about this in his interview with Inspector Walker.

170. It is also reasonably possible that even if Mr Grasso did understand the shared intention of Lendlease and Hassarati, that in his professional opinion the alternate method proposed by him was necessary to provide lateral support to the primary and secondary trusses during the course of the demolition. In other words, I could not draw the inference contended for by the prosecution because there is a competing inference that is inconsistent with guilt.

171. There is no evidence that GCE or Mr Grasso were provided with a copy of any demolition methodology presentation after 7 December 2015. I am not satisfied that he did or was asked to turn his mind to all of the steps necessary to complete the demolition of the building. GCE was asked to give specific advice on discrete issues. GCE was not asked to design and document the demolition methodology from start to finish. Hassarati and Lendlease developed the design and Hassarati sought specific engineering advice from GCE in relation to specific parts of the process.

172. The demolition methodology presentations were prepared for the purposes of Hassarati and Lendlease. Lendlease required the preparation of the QCUA Demolition Methodology presentations as a means of ensuring that the demolition, which was high risk work, was adequately planned and that safety had been considered at each step. The presentations were given to members of Lendlease’s safety managers for peer review. Hassarati needed Lendlease’s approval of the demolition methodology contained in the presentations before it could start the work.

173. It is fair to say that the methodology set out in the 14 December 2015 sketch was not easily applicable to the roof structure in Bays 7 and 9 in particular. With the benefit of hindsight, GCE’s advice was unclear on this aspect but it was not questioned by Mr Khoury, probably because of his subjective understanding that all structural members within a bay were to be removed. I will return to this issue under the next heading.

174. The prosecution argued that I should draw an inference that Mr Grasso had seen the Hassarati sketch on or before 17 December 2015, because of the entry in GCE’s tax invoice dated 29 December 2015 relating to a meeting between Mr Grasso and Mr Khoury for a ‘final review of the demolition methodology’. I cannot and would not draw that inference for the following reasons. There is no date on the tax invoice for that meeting. The tax invoice immediately preceding it was dated 19 December 2015. I would infer that if Mr Grasso had completed work on 17 December 2015 that it would have been included in the tax invoice dated 19 December 2015. The entry in the tax invoice dated 29 December 2015 does not provide a factual basis for me to infer what Mr Grasso did or saw in that meeting with Mr Khoury.

175. I have carefully reviewed the interview between Mr Grasso and Inspector Walker. I do not think that it demonstrates any consciousness of guilt on the part of Mr Grasso. It is fair to say that at times, Mr Grasso was hesitant with some of his answers, but not in such a way that I would draw an adverse inference. Mr Grasso was being formally investigated in relation to matters that concerned his professional reputation and had serious potential adverse consequences. The interview was conducted about six or seven months after the relevant events. Mr Grasso was shown documents by Inspector Walker that was not a complete set, was of poor quality and not the best evidence of some of the relevant matters. There were some answers that supported GCE’s case to the effect that there was significance in the order of demolition of the structural members of the roof structure and that the decision to leave in place some structural members, was deliberate. There were some answers given by Mr Grasso that were adverse to the interests of GCE and I have referred to those answers elsewhere.

176. GCE’s advice as to the non-removal of some structural members was reflected in the Hassarati sketch. The 11 February 2016 sketch and the Hassarati sketch both left the same structural members in place in Bay 4. It was open to GCE to infer that Mr Khoury understood the 11 February 2016 sketch because he faithfully reproduced the essential elements of it in the Hassarati sketch.

177. Taking into account all of the evidence, I am not satisfied beyond reasonable doubt that Mr Grasso made an error in preparing the 14 December 2015 sketch or by approving the Hassarati sketch by adopting it as the 11 February 2016 sketch. It is reasonably possible that Mr Grasso did not mark some of the structural members in Bay 3 and 4 because he intended that they were to be retained to provide structural stability during the demolition of the roof structure.

Was GCE’s advice sufficient to convey that particular structural members were to be left in some bays to provide structural stability for the roof structure during the demolition?

178. The prosecution’s alternate argument was that the documents provided by Mr Grasso did not state that the unmarked structural members in the representation of Bays 3 and 4 were to be left in place for structural stability during the course of the demolition and that the failure to do so led to the demolition proceeding in the way that it did. This is also an essential fact in the reasoning process and must be proved beyond reasonable doubt.

179. The defence case was based on the argument that GCE’s advice was not followed by the removal of all of the structural members from within a bay, when some of those structural members were not marked for removal by Mr Grasso on the relevant sketches. [3]

     3. The 14 December 2015 sketch and the 11 February 2016 sketch.

180. The DW Code provided that the demolition of ‘special structures’ that were complex or unusual because of the nature of their construction required proper planning and care to be demolished safely. The DW Code provided that an appropriate demolition method and sequence should be selected before the work commences and that an assessment of the demolition plan and demolition method by a structural engineer may assist with this process.

181. The evidence of Professor Rasmussen and the demolition workers was that the roof structure was large and complex and highly unusual. I am satisfied that the defendants knew by reason of Mr Grasso’s inspection of the premises, his access to the drawings and his knowledge of the DW Code, that the roof structure of the premises was a ‘special structure’ as referred to in the DW Code.

182. In cross-examination Mr Whitten accepted that in his experience the provision of drawings and diagrams with instructions on them was a common way for structural engineers to convey their advice as to a demolition sequence.

183. Mr McDermott produced a demolition sequence document prepared by a structural engineer, relating to the demolition of concrete walls in the basement of a building at Barangaroo (Exhibit 30). That work involved the demolition of walls in a basement where the building had been constructed on top of them and it was always intended that those walls would be removed when the construction of the building reached a certain stage. Exhibit 30 set out that the concrete walls were to be removed in 1m x 1m sections, one at a time in a particular sequence, with the 1m blocks referred to by a numbering system. It also provided a method of concrete sawing that was to be used and specified that the demolition procedure was to be reviewed by the structural engineer and that certain areas were to be visually monitored during the demolition.

184. In the present case, none of the relevant sketches [4] dealt with the demolition of Bays 7, 9, 2 and 5 that had a different structural configuration to Bays 3 and 4 that had been depicted in the sketches. The most relevant of these sketches was the 11 February 2016 sketch, because it was the last sketch seen by Mr Grasso and approved by him. Further, by issuing the 11 February 2016 sketch and the 11 February 2016 Engineer’s Certificate, GCE was no longer maintaining that the demolition scheme was preliminary and to be further refined after soft strip out.

     4. The 14 December 2015 sketch, the Hassarati sketch, the 11 February 2016 sketch and the Arnold sketch.

185. Bays 3 and 4 had the same structural configuration as Bays 1 and 6, which was very similar (if not identical) to the structural configuration of Bay 8. Bays 7 and 9 had a different structural configuration consisting of radial trusses extending out from the intersection of T4 and T5 in Bay 9 and from the intersection of T4 and T8 in Bay 7.

186. No express instruction was given by GCE as to whether or not any part of Bays 7 and 9 were to be retained. There were two possible interpretations of what should occur, either, no structural members should be left in Bays 7 and 9 or the representation of Bay 4 should be adapted to suit those bays.

187. No express instruction was given by GCE in relation to Bays 2 and 5. It was not possible to adapt the representation of Bay 4 to Bay 2, because Bay 2 only had secondary members running in an east-west direction with no perpendicular members. I cannot discern from the evidence if it was possible to adapt the representation of Bay 4 to Bay 5.

188. Accordingly, if it is accepted that GCE’s advice was to retain certain structural members within a bay, it was not clear which members were to be retained, if any, in Bays 7, 9, 2 and 5. This left open the possibility that demolition workers could interpret the 11 February 2016 sketch in a way that was inconsistent with GCE’s advice.

189. None of GCE’s documents given to Hassarati specified that the structural members to be retained (as represented in Bay 4) were required to maintain the structural integrity of the roof structure during the demolition. If this was an essential element of GCE’s advice, I am satisfied that it should have been stated to prevent any possible misconstruing of the advice. I am satisfied that Mr Arnold would not have interpreted the 11 February 2016 sketch as he did if that statement was included in the 11 February 2016 sketch or the certificate.

292. There was no evidence that as at 8 March 2016 the workers at the premises had devised an actual sequence to be followed. To the contrary the evidence was that Mr Ghababche and Mr Hayward decided on the next bay to be demolished according to the circumstances as they existed from time to time. Accordingly, I cannot infer that Mr Grasso could have been given that information on 8 March 2016.

293. There was no evidence that Mr Grasso was asked to attend the site again after 8 March 2016. In the 7 December 2015 review meeting, Lendlease had specified that it wanted Hassarati to arrange for Mr Grasso to inspect the progress of the demolition every 2 weeks. The remaining roof structure collapsed on 19 March 2016 and within 2 weeks of the 8 March 2016 site visit.

294. The photographs established that all but one of the structural members in Bay 2 had been removed. The structure of the roof of Bay 2 was unique, in that the minor trusses ran in an east-west orientation only and there were no perpendicular structural members.

295. As at 8 March 2016 it was not apparent from the state of the demolition that GCE’s advice had not been followed.

296. This particular focusses on the ‘actual dismantling methodology and sequence’. The prosecution submitted that Mr Grasso should have had created a computer model, from which he could have predicted the collapse by analysing the actual demolition sequence.

297. The difficulty with this submission is that there is no evidence to suggest that Mr Grasso was informed of the intended sequence of demolition of the bays. Without that information there were 362,880 possible combinations of the order in which the bays could have been demolished.

298. I am not satisfied that Mr Grasso (and thereby GCE) knew that GCE’s approved methodology was not being followed either on or after 8 March 2016. I am not satisfied that Mr Grasso (and thereby GCE) had the opportunity to assess the state of the demolition work before the remaining roof structure collapsed.

299. I am not satisfied beyond reasonable doubt that GCE or Mr Grasso breached their duties by failing to advise on the actual demolition methodology and sequence, when Mr Grasso was not advised of the intended sequence and was not asked to inspect the progress of the demolition between 8 March 2016 and 19 March 2016.

(c)   The defendant, as the structural engineer, should have provided demolition specifications and procedures in respect of specifying the methodology and sequence of demolition that most appropriately managed the risk; and/or

302. The prosecution advanced its case under this particular in an odd manner by arguing what GCE failed to do or what it did wrongly, rather than by specifying the advice it should have given, which would seem to be the impetus of the pleaded particular.

303. The prosecution in its final submissions contended that GCE breached its section 19(2) duty by:

1. omitting to specify that Bay 5 should not be left towards the end of the demolition of the roof structure; and/or

2. advising that the bays could be demolished in any order; and/or

3. providing the 11 February 2016 and 9 March 2016 Engineer’s Reports.

Bay 5 should not be left towards the end of the demolition

304. GCE’s advice was clear that the roof structure could be demolished bay by bay, in any order. The prosecution’s argument is not easily understood. It was not suggested that Mr Grasso should have advised Hassarati to demolish Bay 5 first, but that he should have advised not to leave it ‘towards the end’. The argument is imprecise and invites doubt.

305. In his interview Mr Grasso told Inspector Walker that he ‘would have assumed’ that the weight in the centre of the structure, from the ancillary fixtures underneath Bay 5, would have been removed first before the other panels were removed. Mr Grasso stated that if he had told Hassarati to do this, then it would have been referred in the documents. There was no evidence that Mr Grasso gave that advice to Hassarati in the documents.

306. I am satisfied that GCE did not advise Hassarati to demolish Bay 5 first.

307. The evidence of the Experts established that Bay 5 did not have to be demolished first. The actual demolition sequence as modelled demonstrated acceptable load factors after the fifth bay, Bay 7 had been demolished. The alternate sequence proposed by the Experts had Bay 5 being demolished as the fifth in sequence while maintaining acceptable load factors. The Experts did not model any of the other possible combinations.

308. Prof Rasmussen opined that if he had been asked for his opinion that he would have advised that Bay 5 be demolished first, if that was practical and safe to do so from a buckling perspective. The evidence does not establish that it was practical and safe to do so because the Experts did not model this possibility.

309. Dr Bambach’s evidence was that he thought to resist buckling that the heaviest loads on the structure under Bay 5 would have been removed before they were in the actual sequence followed. In my view, this opinion does not add much to the analysis of this particular.

310. The evidence establishes that leaving Bay 5 to be demolished in accordance with the actual demolition sequence of the bays, was a cause of the unplanned structural collapse. The evidence does not identify how late Bay 5 could have been left in the process, without causing a risk of collapse, because only 2 possible sequences were modelled. It is reasonably possible that there was an alternative order of demolition in which Bay 5 could have been left later in the only sequence to be modelled by the Experts.

311. I am not satisfied beyond reasonable doubt that it was reasonably practicable for GCE to advise Hassarati that Bay 5 should not have been left towards or near the end of the demolition of the roof structure.

Any bay can be demolished in any order

312. This part of GCE’s advice was unequivocal and I am satisfied beyond reasonable doubt that GCE advised that any bay could be demolished in any order whilst retaining the structural integrity of the roof.

313. I am also satisfied that GCE’s advice to this effect was relied on by Lendlease, Hassarati and Rosenlund because Mr Ghabache and Mr Hayward were permitted to determine the demolition order of the bays of the roof structure.

314. The expert evidence demonstrated that the actual sequence of demolition of the roof structure gave rise to a risk of unplanned structural collapse, which in fact occurred on 19 March 2016. The Experts opined that this came about as a result of the weight of the ancillary structures under Bay 5, the weight of the remaining structure and the lack of lateral restraint of T5 and T6 east of Bay 5.

315. For the reasons already given I have found that it is reasonably possible that the demolition of the roof structure did not proceed in accordance with GCE’s advice in one respect, by removing structural members that were not marked for removal by Mr Grasso. The Experts gave evidence that if those structures had been left in place that they would have provided some additional lateral restraint for the primary and secondary trusses, but they had not modelled the GCE advice alternative. However, for the reasons given the failure by GCE to state that the structural members not marked were necessary to maintain the structural integrity of the roof structure during the demolition, led to the roof structure being demolished in the way that it was and accordingly the GCE advice alternative can be put aside.

316. For the reasons already given, I am satisfied beyond reasonable doubt that the any bay in any order advice should not have been given in the absence of a computer model, but that argument was not advanced by the prosecution as relevant to establishing this particular. It is therefore not appropriate to find the particular established on that basis and in any event, to do so would not add anything to my earlier finding.

GCE should not have provided the 11 March 2016 and 9 March 2016 Engineer’s Reports

317. The prosecution put its case in two alternative (or cumulative) ways. First, Mr Grasso made an error in shading only part of Bays 3 and 4 in the 14 December 2015 sketch because it was always GCE’s intention to demolish all of the bay except for the primary and secondary trusses. Or second, that Mr Grasso should have made more explicit marking on the drawings to make it clear that he wanted part of the bays retained.

318. As to the first argument, for the reasons already given I am not satisfied beyond reasonable doubt, or generally that Mr Grasso made the error contended for. The evidence does not support the conclusion that Mr Grasso was aware of the common understanding of Lendlease and Hassarati. Alternatively that even if Mr Grasso knew of that common understanding, it was reasonably possible that his advice was deliberately in contradiction of that position.

319. As to the second argument, for the reasons given GCE’s advice was deficient in that it did not state that the structural members not marked were to be retained and were necessary for the structural stability of the roof structure during the demolition process.

320. For the reasons already given, I am satisfied beyond reasonable doubt that the advice conveyed in the 11 February 2016 and 9 March 2016 Engineer’s Reports should not have been given in the absence of a computer model. To the extent that the prosecution repeated its arguments that I have already dealt with, there is no utility in revisiting those matters.

321. I am not satisfied beyond reasonable doubt that the prosecution has established this particular beyond reasonable doubt.

(d)   The defendant, as the structural engineer in relation to the demolition work, should have in the course of the demolition work, advised and provided guidance that temporary supports should be applied to the structure to carry the structural loads during the demolition work and to minimise or decrease the risk of unplanned structural instability, ie lateral buckling; and/or

322. The DW Code provides that the building or structure to be demolished should be maintained in a safe and structurally stable condition so as to prevent the unexpected collapse of part of the structure. It provides that temporary propping may be necessary to ensure that the stability of the structure is maintained.

323. AS 2061 provides that consideration should be given to undertaking demolition in reverse order of construction. That is not to say that the reverse order of construction must be employed in a demolition.

324. The structural drawings indicted that temporary towers at the intersections of the primary and secondary trusses were used to support the roof structure during its construction. The towers were removed when the roof structure was complete.

325. The evidence of Mr Khoury and Mr Hayward was that the roof sheeting would have been installed by workers working on the roof.

326. Lendlease had a safety system in place known as Global Minimum Requirements (GMRs). The GMRs was a document sent out to contractors by Lendlease specifying a set of rules to be complied with by each trade when work was conducted on a Lendlease site. The GMRs specified the way in which some work was to be done as well as preventing work from being done in particular ways.

327. Mr Khoury gave evidence that the GMRs prevented workers on Lendlease sites from undertaking work using harnesses, without specific permission from Lendlease management, which he believed would be ‘almost impossible’ to get. In Mr Khoury’s view this precluded demolition of the roof structure by employing the reverse order of demolition method provided for in AS 2061 because the roof sheeting would have been affixed by having workers physically present on the surface of the roof. Mr Khoury’s evidence was that mechanical methods of demolition were now preferred as being safer because they reduced the need for workers to be exposed to the risk of falls form height.

328. Mr Khoury’s evidence was that he did not consider the use of temporary propping at any time during the tender process for the demolition of the roof structure. He did not factor that possibility into his lump sum tender price. He intended during the tender process to demolish the roof structure using an excavator, but had not worked out all of the details of the plan.

329. Mr Khoury’s evidence was that he did not discuss with anyone from Lendlease or Mr Grasso the use of temporary propping of the primary and secondary trusses at any time after the tender was accepted and up to the time of the incident.

330. Mr Khoury accepted in cross-examination that the use of temporary propping would have impacted on his decision to use the excavator to demolish the roof structure and that there would have been access issues created. Mr Khoury gave evidence that there may have also been issues with demolished materials falling onto the temporary props. Mr Khoury gave evidence that there would have been some need for footings to be installed onto which the temporary supports could have been installed. Mr Khoury agreed that the construction of the footings may have required some input from a geotechnical engineer.

331. Mr McClutchie gave evidence that if there had been Favco towers erected at the intersection points of the primary and secondary trusses that it would have made his job a bit harder, but it would probably have been worked around. He accepted that the towers would have possibly got in the way of the work, but he could try to manoeuvre around them.

332. The Experts opined that support of the primary and secondary trusses was necessary for the sequence of demolition that was undertaken. The Experts identified an alternative sequence for which support of the primary and secondary trusses was not likely to be necessary. The Experts opined in their second report that the supporting of the roof structure during demolition was not specifically analysed and that generally speaking it was something that could be done and it would have likely decreased the risk. Prof Rasmussen’s evidence suggested that the temporary propping of the roof structure would only have been necessary if the load factors in the structural analysis were assessed to be in the vicinity of 1.0.

333. I am not satisfied beyond reasonable doubt that the prosecution have made out this particular for the reasons that follow.

334. First, GCE was not asked to advise on the demolition using temporary propping. This was not an option that was being considered by Hassarati for the good reason that it would have affected the decision to use the excavator to demolish the roof structure.

335. Second, there was a paucity of evidence led by the prosecution as to the requirements to install temporary propping. The prosecution led no evidence as to the need for foundations to support the temporary props or how the temporary props would be installed. For example, Favco towers which were rasied in the evidence to my understanding are usually installed by the use of a crane, but there was no evidence that a crane could access the premises to install the temporary props in the required positions. When the defendants sought to lead evidence in cross-examination from Mr Khoury, as to the requirements for foundations and the like, the prosecution complained that he did not have the relevant experience to comment on those matters. In my view, the prosecution has not discharged its onus on this issue.

336. Third, I am not satisfied that it would have been reasonably practicable to use the excavator with the temporary props installed. Mr McClutchie’s evidence on this point was in my view equivocal.

337. Fourth, the evidence of the Experts established that the use of temporary propping was not required if the demolition had been conducted in accordance with their alternative sequence.

Conclusion on Element 3 and Element C

338. I am satisfied beyond reasonable doubt that the prosecution has established Element 3 of the section 19(2) offence.

339. I am satisfied beyond reasonable doubt that the prosecution has established Element C of the section 27 offence.

Element 4 - Did GCE’s breach of duty expose Messrs McClutchie and Hayward to a risk of death or serious injury?Element D - Did Mr Grasso’s breach of duty expose Messrs McClutchie and Hayward to a risk of death or serious injury?

340. The principles relevant to causation are set out at [232] to [234].

341. It should be reiterated that the question to be determined is not whether GCE’s advice caused the unplanned structural collapse on 19 March 2016, but whether GCE’s advice was a significant or substantial cause of the Rosenlund workers being exposed to a risk of serious injury or death.

342. For the reasons already given I am satisfied beyond reasonable doubt that GCE and Mr Grasso were each in breach of their health and safety duty by reason of the failure to create a computer model to assess the risk of unplanned structural collapse and by giving the advice contained in the 11 February 2016 sketch, the 11 February Engineers Certificate and the 9 March 2016 Engineers Report.

343. The risk of unplanned structural collapse was a known risk identified by the DW Code and AS 2601. Hassarati sought advice from GCE to eliminate or minimise that risk and I am satisfied that GCE and Mr Grasso knew that was the purpose of the request for advice.

344. GCE provided advice on 3 occasions, 14 December 2015, 11 February 2016 and 9 March 2016, without conducting an appropriate engineering analysis by way of computer modelling. The creation of a computer model was a reasonably practicable measure that would have allowed GCE’s advice to be tested, thereby eliminating or minimising the risk of an unplanned structural collapse. In the absence of the computer model, GCE’s advice did not eliminate or minimise the risk of an unplanned structural collapse. The exercise of Mr Grasso’s engineering judgement was fallible, resulting in the potential for the risk to come home during the course of the demolition.

345. GCE contended that its advice was that the unmarked structural members on the 11 February 2016 sketch were not to be removed and that the prosecution has failed to prove that the GCE advice alternative would have led to the risk of an unplanned structural collapse. If that was GCE’s advice, for the reasons already given I am satisfied beyond reasonable doubt that GCE failed to adequately communicate in the 11 February 2016 sketch and certificate that the unmarked structural members were not to be demolished because they were necessary to provide structural stability to the roof structure during the demolition of the roof structure.

346. I am satisfied that GCE’s failure to adequately communicate its advice led to the interpretation of the 11 February 2016 sketch adopted by Mr Arnold and incorporated into the Arnold sketch. The Arnold sketch depicted that all of the structural members were to be removed from each bay. The Arnold sketch was then used to instruct the Rosenlund workers on how the demolition was to be undertaken, with the result that all of the structural members were removed in each bay.

347. From 11 February 2016 onwards, the unequivocal part of GCE’s advice was that any bay of the roof structure could be demolished in any order and still maintain the structural integrity of the roof.

348. I am satisfied that Lendlease, Hassarati and Rosenlund relied on GCE’s advice that any bay could be demolished in any order , because Mr Ghabache and Mr Hayward were permitted by the demolition methodology to determine for themselves the order of demolition of the bays.

349. The expert evidence demonstrates that the order of demolition of the bays of the roof structure was significant when it came to the structural stability of the remaining structure. Mr Grasso himself recognised this in this interview with Inspector Walker in that he assumed that the weight of the ancillary fixtures underneath Bay 5 would have been removed as a first step in the demolition. The evidence demonstrates that GCE did not advise Hassarati to demolish Bay 5 or to remove the weight of the ancillary fixtures under Bay 5 as a first step in the demolition.

340. This led to the position that Bay 4 and Bay 5 were left intact as the last two bays to be demolished. The weight of the remaining structure and the ancillary fixtures under Bay 5 placed significant loads on T5 and T6 which were unrestrained east of Bay 5, resulting in lateral torsional buckling of T5 and T6 and the unplanned structural collapse.

341. I am satisfied beyond reasonable doubt that GCE’s advice given in breach of its section 19(2) duty was a significant or substantial cause of the Rosenlund workers being exposed to a risk of unplanned structural collapse.

342. I am satisfied beyond reasonable doubt that Mr Grasso’s failure to take reasonable steps to ensure that GCE’s advice was properly considered in breach of his section 27 duty was a significant or substantial cause of the Rosenlund workers being exposed to a risk of unplanned structural collapse.

343. I am not satisfied that the way in which Bays 7 and 9 were demolished represented a significant departure from GCE’s advice, because there was no express advice given on how those bays were to be demolished which gave rise to the workers exercising their own discretion.

344. I am satisfied beyond reasonable doubt that the prosecutor has proved Element 4 and Element D of the offences.

Conclusion

355. The prosecution has proved all of the elements of the offence beyond reasonable doubt.

356. I find Grasso Consulting Engineers Pty Ltd guilty.

357. I find Ignazio Grasso guilty.

358. I will list the matters for sentence on a date convenient to the parties.

Endnotes

Decision last updated: 05 February 2020