Feds Fault University, Florida Agency and Contractors for Deadly Bridge Collapse
WASHINGTON — During a hearing Tuesday on last year’s deadly collapse of the Florida International University pedestrian footbridge, the National Transportation Safety Board heard evidence from its staff engineers and investigators showing that the bridge’s “catastrophic failure” stemmed from a flawed design with “significant errors.”
In addition, investigators found that the university, the Florida Department of Transportation, and the project’s engineers and contractors failed to exercise independent judgment, or even common sense, in leaving the busy road underneath the bridge open while a construction crew performed emergency work.
Before the collapse, “abnormal” cracks had been growing and spreading throughout a crucial support junction at the span’s north end, left critically weakened by a major design error, NTSB investigators told the board at an ongoing hearing in Washington Tuesday morning. But no one acted to close down the road.
The cracks were “screaming that there was something definitely wrong with this bridge and yet no one was listening,” said NTSB Chairman Robert Sumwalt.
“I’ve been on this board for 13 years and I don’t think I’ve seen (an accident) where there’s more finger-pointing between the parties,” Sumwalt added. “And, you know, the finger-pointing is correct … because everyone shares a piece of this accident.”
The bridge was designed by Tallahassee-based FIGG Bridge Designers. The firm’s engineering work was repeatedly criticized at the hearing, as was its failure to realize its design was failing in plain sight.
The fatal accident remains the subject of an ongoing criminal investigation by police and prosecutors in Miami-Dade County. Six people died on March 15, 2018, when the 950-ton span collapsed onto cars idling on Tamiami Trail. Ten others were injured.
The federal investigative agency — which cannot issue sanctions in its cases — is expected by the end of the day to release a final report outlining the accident’s probable cause, as well as the board’s major findings and safety recommendations.
The immediate cause of the collapse came when workers tried to tighten internal steel support bars in an attempt to close the cracks, as ordered by FIGG’s top engineer on the project, W. Denney Pate. That operation “push(ed) the concrete beyond its limits … causing it to fail,” the NTSB said Tuesday. The repair work was not called for in the original plans and had not been independently reviewed.
“Staff concluded that retensioning … was a change to the design plans that should have been reviewed, signed and sealed by a professional engineer, none of which were done,” said Steven Prouty, senior highway engineer in the NTSB’s Office of Highway Safety.
Prouty said the parties behind the bridge — including FIU, FDOT, FIGG, general contractor Munilla Construction Management and inspectors Bolton Perez & Associates — could have called for the road to be shut down while the emergency work was taking place.
“None of them acted on that authority,” he said.
After hearing the NTSB staff presentation, Bruce Landsberg, the board’s vice chairman, called the accident “astounding.”
“FIGG has been very experienced and they’ve been building bridges for decades and I’m amazed this situation could happen,” he said.
Serious cracks had started opening in the bridge weeks before the collapse — the result of the design error that left the span drastically underdesigned for the load it was supposed to bear. While cracking in concrete is not uncommon, the cracks growing through the FIU bridge were “40 times larger than what is typically considered acceptable,” the NTSB said Tuesday. But no one overseeing the project seemed to believe they were a safety threat or even discussed closing the road.
The main entities behind the project have largely stayed silent since the accident, citing the NTSB’s policy that no one should release information during an investigation. Now, after 19 months, the investigation is over. So far, the parties have said little.
FIGG claims a construction error, not a design mistake, led to the accident, although three federal agencies have now disagreed with that assessment and on Tuesday the NTSB said that while the construction error, which involved failing to “roughen” concrete at the crucial joint, did occur, it did not cause the collapse. FIGG hired its own forensic engineers who disputed the government’s findings.
Sumwalt, the board chairman, countered FIGG’s assertions. “We’re the only organization involved that doesn’t have a dog in the fight,” he said. “Our purpose is to find out what happened so we can keep it from happening again.”
Meanwhile, the NTSB also faulted the state’s lack of oversight. FDOT has acknowledged the road should have been closed.
“In addition, because the pedestrian bridge was a unique and complex design, Florida DOT should have provided more oversight as the supervising agency for this project, ensuring that it was designed and constructed according to specifications,” Prouty said. “This distress in structural cracking was documented by FIU, FIGG, MCM, Bolton Perez and Florida DOT. None of these parties took the responsibility for declaring the cracks were beyond any level of acceptability and did not meet Florida DOT standards.”
Another entity that came in for criticism at Tuesday’s hearing was Louis Berger, a global engineering firm hired to independently review FIGG’s design. FIGG had originally wanted to do the “independent review” itself, something rejected by FDOT. FIGG then turned to Berger, which was not qualified under state rules to perform such review work on a complex concrete bridge. Somehow, no one objected.
“FIGG’s failure to adhere to the Florida DOT’s requirements in initially contracting for an independent peer review firm and Louis Burger’s inadequate peer review resulted in significant errors in FIGG’s design to go undetected,” said Dan Walsh, a senior highway accident investigator at the NTSB. “This underdesign led to the bridge’s structural failure and collapse.”
Walsh also pointed out that FIGG’s design was not redundant — meaning if one element like the crucial node failed, the whole bridge would come down.
Sumwalt said the bridge’s failure can be summarized in three parts.
First, FIGG’s design of the bridge underestimated the demands placed on the structure and overestimated the structure’s strength. Second, the peer review conducted by Louis Berger was inadequate. And third, none of the parties involved in the bridge’s construction with the power to close the road recognized the seriousness of the errors.
“A very complex situation, but it really boils down to those three points,” Sumwalt said.
Before the collapse, Pate, FIGG’s chief engineer, insisted to other engineers and contractors that the cracks did not pose a safety threat, even though he and his team told investigators they did not understand why the cracks were forming.
Victims and their families have largely settled the lawsuits filed after the accident. Now, their attention may turn to whether Miami-Dade State Attorney Katherine Fernández Rundle plans to file criminal charges. The NTSB ruling may shed light on whether the project team’s decision to treat the cracks as minor crossed the line into criminal negligence.
But bringing a criminal case against contractors in a construction accident is difficult under Florida law. Fernández Rundle faced criticism for saying the day after the collapse, before any significant evidence had been gathered, that she saw criminal charges as “improbable.”
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Miami Herald staff writer David Ovalle contributed to this report.
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