Mall Collapse: ‘Failure of Engineering’
Dubious designs, structural workarounds, untested waterproofing decisions, and other factors laced with misgivings all contributed to the massive collapse of an Ontario shopping mall last summer, according to a judicial inquiry now underway.
From the project architect to engineers to the waterproofing contractor, witnesses and evidence in the inquiry's first week described shoddy construction methods, severe water problems, questionable structural design, and untested waterproofing methods dating back more than 30 years at the Algo Centre Mall in Elliot Lake, Ontario.
The mall's rooftop parking deck caved in June 23, 2012, fatally crushing two women—Lucie Aylwin, 37, and Doloris Perizzolo, 74—and injuring more than 20 people.
The Elliot Lake Commission of Inquiry public hearing, directed by Commissioner Paul Belanger, is a judicial inquiry—not a trial—aimed at determining the cause of the collapse.
'Who's at Fault'
“We’re looking forward to the evidence that establishes who’s at fault,” attorney Roger Oatley, who represents the families, told reporters before the hearing opened.
The structure, built in the late 1970s and opened in 1980, is now being demolished.
The first week of the hearing was dominated by several themes, including second-guessing of the structure's rooftop parking design—even from those who designed it.
On Monday (March 11) designer James Keywan told the commission that he had been "very uncomfortable" with the design, but that the original owner felt it was the best and cheapest option.
“I’m very uncomfortable with that because there’s retail space below,” Keywan testified. “I had never done it. It’s not a common thing to do.”
'Failure of the Engineering Profession'
In opening remarks Monday (March 4), attorney Doug Elliott called the mall disaster "a failure of the engineering profession of Ontario.”
“A shopping center mall should not just fall down,” said Elliott, who represents some local families.
Investigators believe water and salt penetration rusted out a critical weld on the underlying support structure. Engineering evidence will thus be a cornerstone of the inquiry, and thousands of documents are expected to be released as the hearing progresses.
To that end, Belanger ordered the Association of Professional Engineers of Ontario in January to produce documents related to complaints about some of its engineers.
The association fought the request, citing member confidentiality. But Belanger said that public interest in the case outweighed those claims and that individuals could still contest certain disclosures on a case-by-case basis.
The first week's testimony centered on the design of the parking structure and efforts to waterproof it.
News reports detailed the first-day testimony of structural engineer John Kadlec, who signed off on the project more than 30 years ago, despite substantial evidence at the time of multiple structural problems.
“I’d never seen that many deficiencies in my life before,” testified Kadlec, who worked for Beta Engineering of Toronto. “I sent letters warning [the owner] about sloppy workmanship.”
Kadlec described missing bolts, crooked columns and corrosion on new steel beams. To remedy the crooked columns, construction company York Steel anchored the building to an adjacent rock face, Kadlec testified, according to reports.
“I’d never seen that many deficiencies in my life before,” testified structural engineer John Kadlec, who approved the mall project in the 1970s.
Inspection reports from 1980, when the mall opened, were also introduced Wednesday. Those reports noted several deficiencies, including the leaning columns, reports said.
Kadlec also testified that he had been puzzled by the “unique” decision to put an exposed parking structure in Canada atop the mall rather than underground.
“I didn’t like it, especially in this area,” Kadlec said. “We talked about it. I was a small man, but the decision was made somewhere else.”
In the end, however, he signed off on the project after reports from an inspection company indicated that the problems had “apparently” been rectified.
Kadlec said he knew that the structure began to leak right after it opened. Immediately after the collapse, reports emerged about the mall's history of leaks. In the year before the collapse, business owners complained about leaks, and one tenant successfully sued the mall's owner.
Douglas Harman, of Coreslab, which made the concrete roof slabs, testified that the project architect, not Coreslab, was responsible for waterproofing decisions.
CBC News of Ottawa reported that Kadlec's engineering license was suspended for "a period of time in the 1990s over problems with several other building projects." The Professional Engineers of Ontario reinstated the license in 1999, the news outlet reported.
Waterproofing Contractor Lays Blame
On Thursday and Friday, the mall's waterproofing contractor told the commission that his company had tried repeatedly to stop the leaks, whose source remained a "mystery." He finally concluded, he said, that the problem was beyond waterproofing.
"I think the No. 1 factor in my mind was the choice of the structure framing system," testified Dave Monroe, a former vice president at the Michigan-based Harry S. Peterson Co. "Not the steel, but the hollow core."
The roof deck was built of precast hollow-core slabs, rather than a seamless or large concrete pad, over steel beams.
"There were too many slabs of hollow-core precast concrete loosely tied together," said Monroe, "and they moved more than we would have expected and in ways we didn't expect."
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The mall's rooftop parking deck began leaking as soon as the structure opened in 1980. Rust was found on new steel beams. A 1992 engineering report called the design "inappropriate in achieving a water-tight condition."
Doug Harman, an executive of slab provider Coreslab Structures, testified earlier in the week that his company had installed the concrete but made no recommendations about waterproofing. He said that was the responsibility of the architect.
'Pressure to Get this Work Done'
Monroe said his company had installed a type of waterproofing system that it had not used before on that type of structure.The system involved using a composite sealant and polyurethane membrane only at critical joints in the concrete, rather than applying a membrane across the entire surface.
He said the mall's original owner had opted for that $380,000 approach rather than a conventional system that would have cost $150,000 more.
Once the contract was signed, the mall owners pressed the contractor to finish the job quickly, despite bad weather.
"There was a lot of pressure to get this work done before the hard winter set in,” Monroe testified.
A series of letters from Algocen to Peterson outlined ongoing problems between the parties, with the owners demanding "urgent action.”
“A complete summer has gone by and your company has not been able to correct these deficiencies and give us what we contracted for—namely a water-tight parking deck and canopy," Algocen wrote Monroe in November 1980.
Efforts to repair and waterproof the leaking garage failed so repeatedly that contractor Dave Monroe wondered why the mall owner "didn't sue us."
Monroe recalled last week: "We realized we had problems we did not understand. It was very disheartening."
The leaking defied so many attempted repairs, Monroe testified, that he finally wondered "why they didn't sue us." He added: "That must have been their decision."
Ten years later, a 1992 engineering report just released in the case concluded: "The design used for this roof slab is inappropriate in achieving a water-tight condition."
Maintenance of the mall will likely be another focus of the investigation.
In January, Belanger denied a request by current mall owners Robert Nazarian and his son Levon to keep their company's financial information secret.
“The open-court principle is of particular importance in the context of this type of public inquiry,” said Belanger, who also denied the owners' request for taxpayer funds to pay their legal bills during the hearing.
Belanger said the Nazarians’ financial situation was germane to the investigation, The Globe and Mail reported.
“The mall owners’ financial circumstances are directly relevant and of significant importance,” the commissioner's ruling said.
More than 75 witnesses are scheduled to testify at the hearing, which is expected to last until mid-summer.