Elliot Lake: How could so many engineers be so wrong?

A damning new report—including an animated recreation of the collapse—emerges at the public inquiry

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A screen capture taken from an animated recreation of the mall collapse.

An engineering firm hired by the Ontario Provincial Police to conduct a forensic investigation into last summer’s deadly mall collapse in Elliot Lake has issued a damning indictment of its fellow engineers—from the man who stamped the structural design of the doomed structure to the many inspectors who failed to recognize how dangerously unstable the building had become.

In a report tabled Tuesday at the public inquiry probing the Algo Centre cave-in, experts from NORR Ltd. concluded that the steel beams and bolts that held up the ill-fated rooftop parking lot were so thoroughly rusted by three decades’ worth of salty slush and rain that they resembled something from a “marine environment.” Yet the severe water damage, obvious to so many shoppers and tenants, repeatedly “went unnoticed or grossly underreported” by the professionals who should have spotted the warning signs.

“None of the engineers’ reports raised an alarm regarding the corroding steel frame nor did they suggest any requirements to monitor the corrosion,” reads the 142-page report, dated March 8. “The clean bill of health given to the structure by a number of consultants in the past few years before collapse is quite alarming.”

Like its preliminary findings, submitted to the OPP last November, NORR’s final analysis confirms the precise cause of the collapse: one particular weld, connecting a horizontal steel beam to a vertical column, was so corroded by years of moisture that it simply couldn’t hold any longer. By the afternoon of June 23, 2012, the welded connection could withstand only 13 per cent of its original capacity. Two cars—one parked, the other driving by—were “the last straw,” the engineers concluded.

At precisely 2:18 p.m., the connection buckled, sending thousands of pounds of concrete and that parked SUV crashing down on a lottery kiosk below, where two women were standing: Lucie Aylwin, 37, and Doloris Perizzolo, 74. Neither survived; by the time rescue workers reached them, they had been buried in the rubble for nearly four days.

Stamped by Hassan Saffarini, a structural expert who led the NORR investigation, the report recommends creating guidelines to help engineers identify and assess the extent of steel corrosion. Although it may sound surprising, most structural engineers have little experience analyzing rust and decay, at least indoors.

“Occupied steel buildings are assumed to be kept in dry conditions which are not conducive to corrosion,” the report says. “Inspecting them for corrosion is thus typically not called for, which explains why there are guidelines in Ontario for inspecting bridges but none for buildings.” In fact, the NORR report notes that that Algo Centre collapse was tragically unique. “In digging into the literature,” it says, “one is hard pressed to find a similar example where a carbon-steel framed building in North America or Europe continued to corrode to the point of failure.”

Nevertheless, the NORR report says the leaks from the rooftop parking deck were so pervasive for so long that they “should have spurred a more thorough investigation” of the mall’s structural integrity. “Had such an inspection been carried out in the last ten years or so of the life of the building, it is inconceivable that the severe condition of the steel would not have been detected,” the firm concludes. “A number of actions could have been taken to avoid collapse had the critical condition been identified in time.”

Sadly, the opposite occurred. Engineer after engineer walked through the Algo Centre, expressing no real concern, if any, that all those leaks might be eating away at the welded connections holding the roof together. Two of the last firms to inspect the building—Pinchin Environmental and M.R. Wright & Associates—“issued unequivocal reports attesting to the soundness of the structure.” M.R. Wright’s final thumbs-up was submitted less than two months before the ceiling caved in.

“The history [of the Algo Centre roof] is full of poor engineering, indecision, misrepresentation, bad judgment and negligence,” NORR concludes. “Some of those who were involved were quite professional in dealing with the issues but on the whole a different course of action needed to be taken to avert this tragedy and avoid almost 30 years of terrible occupancy conditions at the mall. Upon reviewing the history, the indirect causes and in some cases the butterfly effect leading to the collapse in 2012 became apparent.”

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The very concept—a giant parking lot directly over retail stores, subject to the wear and tear of northern Ontario winters and the scraping snowplows that go with it—was, in hindsight, “an unfortunate one.” Throw in an “experimental” waterproofing system that was anything but, and the mall’s fate may have been sealed before it even opened its doors. But as NORR makes clear in its findings, that fate could have been altered. There were plenty of other decisions—many involving engineers, licensed and otherwise—that culminated in the events of that Saturday afternoon.

Like a puzzle, the mall’s rooftop parking lot was pieced together with precast, hollow-core concrete slabs (eight inches deep, four feet wide, and for the most part, 30 feet long) laid on top of horizontal steel beams. According to the original structural drawings, stamped by Toronto engineer John Kadlec, those eight-inch concrete slabs would be able to withstand a superimposed load of up to 120 pounds per square foot (and, in some locations, 130 P.S.F.). But as the NORR investigation reveals, Kadlec’s assumptions were wrong—and he apparently knew it.

Precon, a slab company that bid on the original project in the late 1970s, specifically warned the developer, Algocen Realty Holdings, that a slab eight inches deep was not strong enough to carry a superimposed load of 120 pounds per square foot—unless a thin, composite concrete topping was applied. Kadlec, though, assured Algocen that he was correct, and that the slab could withstand such a load without any topping. “A simple review of the suppliers’ design tables would have indicated to Beta Engineering [Kadlec’s firm] that such a system is not achievable,” NORR concluded. Sticking to his original design, “especially after being advised to the contrary by a specialist supplier, is quite troubling.”

Even more troubling was the conduct of Dave Hellyer, an engineer working for Coreslab, the concrete company that eventually won the bid and installed the rooftop parking deck. Even though Coreslab’s own specifications said a concrete slab eight inches deep can hold, at most, a superimposed load of 87 pounds per square foot, Hellyer assured the developer that its product somehow met Kadlec’s design of 120 pounds—again, without having to apply an additional concrete topping. Hellyer’s assurances were a clear “misrepresentation,” NORR concludes, “in an aggressive effort to win a competitive tender.”

“The owner was apparently misled into believing that he had bought a system that fulfills the Project’s specification, when it did not,” the report continues, describing Hellyer’s conduct as “beyond explanation.”

Ironically, a three-inch topping was later applied to the Coreslab product after they were installed, all part of the no-membrane “waterproofing” system that proved to be such an utter failure. And in the end, the load-carrying capacity of the slabs had nothing to do with the actual collapse; the soaking wet steel connector holding up the concrete failed, not the slabs themselves. But as the years passed, and those incessant leaks continued, concerns over how much weight the slabs could withstand thwarted many attempts to install a waterproofing system that actually worked. In other words, the choice of slab didn’t cause the problem, but it certainly hindered efforts to fix the problem.

Even Coreslab changed its original opinion of how much weight the slabs could withstand. In 1980, Hellyer assured Algocen that the slabs could meet Kadlec’s design of 120 pounds per square foot without a concrete topping. Twelve years later, as Algocen struggled to fix the leaks, a different engineer working for Coreslab said the three-inch topping was indeed necessary to ensure the load-carrying capacity, and that it could not support any more weight—including a waterproofing membrane. “The limited capacity of the [hollow core slabs] precluded many potentially effective waterproofing options from being installed later on while the leakage persisted,” NORR writes. “The hollow core slab’s inadequacy did not contribute directly to the collapse; however the limited capacity that was inherent in what Coreslab supplied had an indirect effect in foiling the early attempts at stopping the prolonged corrosion process which ultimately led to the collapse.”

Translation: One engineer, John Kadlec, drafted an “improper functional specification,” while another engineer, Dave Hellyer, “misled the owner into believing that they had bought” a product that met Kadlec’s inappropriate design. (In 1994, the organization that regulates Ontario engineers revoked Kadlec’s license because of the “incompetence” and “professional misconduct” he displayed on two other botched designs. A year later, another project he did for Algocen Realty—an extension to the Station Mall in Sault Ste. Marie—endured its own partial roof collapse. Kadlec’s license was eventually reinstated, with limitations, in 1999.)

Despite obvious design and waterproofing flaws, NORR is especially critical of the engineers who came to Elliot Lake after the mall’s construction. According to the report, there were many “missed opportunities to make specific observations that could have averted the collapse” because most of the inspectors seemed oblivious to corrosion on the structural steel framing. “Steel was only casually referred to,” it says, “and even when all the signs were there, say in the five years prior to collapse, it was dismissed as minimum risk.”

In April 1991, 11 years after the mall opened, Algoma Central Properties (as Algocen had come to be known) commissioned Trow Consulting, a Brampton, Ont., firm, to conduct a detailed “investigation” of the parking structure. Though focused on the hollow core slabs, the company did observe surface rust on many of the steel beams. However, “no measurements were reported to verify the amount of section remaining and no mention of connection condition was made.” Three years later, when Trow conducted another on-site visit, the concrete slabs, not the steel beams, were once again the top priority. “The beams appeared to be sound with some surface corrosion,” their report states. As NORR notes, “it is not clear to what extent Trow inspected the steel framing and there is no mention of the condition of the connections” that proved so dire two decades later.

In March 1996, after Kadlec lost his license, Algoma Central sought out an independent engineer to review his structural drawings in Elliot Lake and ensure the design met all applicable codes and standards. Trow responded to Algoma’s request for proposal with a detailed investigation plan that included, for the first time, a “spot check” of the steel connections that, by then, were already destined to fail. Algoma ultimately chose another engineer, Paul Meyer, whose proposal was half the price.

“Meyer concluded that the building had been designed in accordance with the Ontario Building Code in effect at the time of construction and that the construction reviewed on site appeared to be constructed properly with no significant defects observed,” the NORR report states. “There is no specific mention of what was inspected by Meyer on site and corrosion of steel members was not mentioned in his report.”

The mall had 16 years left to stand.

In September 1998, Albert Celli visited Elliot Lake. An engineer at Halsall Associates Ltd., he was retained to conduct a visual structural review, with a focus on the notorious parking deck. At the time, “Retirement Living” (the not-for-profit group that helped transform Elliot Lake from a busted mining town into a go-to destination for seniors) was considering buying the mall and the adjacent 80-room hotel. “From the underside of the parking deck, we observed some corrosion of the structural steel beams and columns, indicating past leaking of the deck,” Celli wrote. Although he found “no evidence of structural distress or excessive deterioration of the structural steel framing,” Cellli did recommend further study of the “beam and bracing connections.”

A year later, Halsall returned to the mall. “Corrosion of the steel beams supporting the precast panels has occurred at leak locations, typically causing the red-oxide coating to be removed by surface corrosion,” the company concluded. “Severe scaling has generally not occurred.” In their report, the NORR engineers said Halsall “did not adequately provide a cautionary warning that future corrosion could potentially lead to the development of a critical condition if left untreated.”

Retirement Living did end up purchasing the mall in June 1999. “While the leakage continued unabated,” the NORR report states, “there does not seem to be any reported major investigation or profound repair project throughout the period of the ownership of [Elliot Lake Retirement Living].”

Before Bob Nazarian bought the property in the summer of 2005, Construction Controls Inc., an engineering consulting firm based in Concord, Ont., inspected the building. Their report described the roof structure as “good” and estimated zero cost for repairs. Although the steel framing was part of the scope of work, the report mentions nothing about rust or corrosion.

The roof was seven years away from caving in.

An inspection by the city of Elliot Lake, conducted in 2006, did find “extensive rust on the structural members and their connections in some areas”—the first suggestion, of any kind, that the welds may be compromised. The city ordered a review by a professional engineer to “ensure structural capacity.” (Bruce Caughill, the Sault Ste. Marie engineer hired to conduct the review, had a “disagreement over payment” with Nazarian and the inspection was never completed.)

In June 2009—three years before weld gave way—Pinchin Environmental Ltd. conducted its own “building condition assessment.” Amazingly, the on-site inspectors found nothing to be concerned about. “They stated that no major deficiencies existed within the visibly accessible components of the structure which would compromise structural integrity,” NORR wrote. “As a result, they called for no major or minor repair of the structural elements.”

That Fall, city and fire officials conducted a second inspection of the mall. Bruce Ewald, now Elliot Lake’s chief building official, found such a long list of deficiencies—the leaky roof, the rusted structural beams, the loss of fireproofing material in the ceilings—that he ordered Nazarian to “have the entire mall area inspected by [a] structural engineer” and “correct all deficiencies” within the next five weeks. Nazarian turned to Bob Wood, the president of Sault Ste. Marie-based M.R. Wright & Associates.

Wood, who has since had his engineering license suspended for his work on an unrelated project, noted “severe areas of leakage” but found “no visual structural concerns.” Included in his October 2009 report is a photograph of the very beam that would collapse 2½ years later. If he ever inspected the welded connection, there is no mention of it in his report. “From the available forensics the connection at the time would have been in an almost failed state exhibiting unmistakable signs of very severe corrosion,” the NORR report states.

In the Fall of 2010, just 18 months before collapse, Nazarian commissioned Read Jones Christoffersen, a respected engineering firm, to study alternatives to the parking deck. The consultants suggested restricting access to most of the roof, installing a waterproofing membrane and using the bulk of the roof as a solar panel farm. “Although the document is thorough in its description of the rehabilitation of the concrete parking deck and the installation of a proper waterproofing system, it does not mention the structural steel framing at all,” the NORR report concludes. “Furthermore no structural inspection report was provided by RJC.”

RJC’s plan never materialized. The company was forced to file a construction lien against Nazarian’s company after he refused to pay the $24,000 consulting fee, and negotiations with the would-be solar panel firm also fell apart after Nazarian demanded it build and maintain an adjacent parking garage.

Bob Wood of M.R. Wright made one final visit to Elliot Lake on April 12, 2012, just ten weeks before the cave-in. In yet another report that proved to be dead wrong, M.R. Wright described the corrosion on the steel beams as “surface rust” and concluded that the members were “still structurally sound.” The NORR investigators were stunned. “The observed evidence of extensive severe to very severe corrosion in the structural steel of the roof parking level framing contradicts such a statement completely,” their report says. “There is no evidence that any measurement of loss of section was made to support this statement. Furthermore, no comment on the connection is made.”

It appears, according to NORR’s expert assessment, that most of the weld on that particular connection had already failed—and was literally hanging by a thread when Bob Wood walked into the mall on April 12, 2012. In fact, NORR believes the “failure actually took place in two events, separated by several months, perhaps a year.”

The first “event”—whatever it was—led to “a reduction of capacity of the connection but did not cause a break,” the report continues. “The weakened connection continued to corrode and eventually sheared off in the second event which took place on June 23, 2012. The significance of the two stage failure is that the depletion of capacity went on for a long time and collapse was in the making for years. It is in fact somewhat surprising that failure did not happen earlier.”

That it actually happened is no longer so surprising. As the NORR report concludes: “There is ample evidence that flags had been raised by workers in the mall, patrons, City inspectors and tradesmen. These warnings were not dealt with duly and effectively. The owners were frustrated with the leakage but were not focused on the structural aspect, perhaps due to a lack of appreciation of the seriousness.”

No thanks to many engineers.

Michael Friscolanti spent months chronicling the events that contributed to the tragedy at the Algo Centre. His findings appear in our new ebook: Doomed: The Untold Story Behind the Collapse of the Elliot Lake Mall, which is available here.