During a hearing Tuesday on last year’s deadly Florida International University pedestrian footbridge collapse, the National Transportation Safety Board concluded that the bridge’s “catastrophic failure” stemmed from a flawed design with “significant errors.”
All of the major parties involved in the project — from the university to the Florida Department of Transportation and the project’s engineers and contractors — came in for harsh criticism during the public hearing, something they have largely avoided as the NTSB conducted a closed-doors investigation over the past 19 months while victims and their families demanded answers.
The NTSB determined that FIU, FDOT, as well as the project’s design-build team and inspectors 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. Six people died on March 15, 2018, when the 950-ton span collapsed onto cars idling on Tamiami Trail. Ten people were injured.
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 a hearing in Washington, D.C. 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.
The unique concrete truss bridge was designed by Tallahassee-based FIGG Bridge Engineers. The firm’s engineering design work was repeatedly criticized at the hearing. So was FIGG’s failure to realize its non-redundant design was failing in plain sight. FIGG’s errors, Sumwalt noted, would have been caught “before concrete was ever poured” if an adequate peer review of the bridge plans had been performed.
“But another structure failed in this accident: the structure of public safety oversight,” Sumwalt explained. “The oversight structure should have resulted in suspension of work and road closures. It did not. Oversight of the project, like the bridge itself, collapsed.”
And he also noted that FIU, which conceived and oversaw the project, could not escape blame for what happened.
“You can contract out your authority, but you can’t contract out your responsibility,” he said.
The fatal accident remains the subject of an ongoing criminal investigation by police and prosecutors in Miami-Dade County.
Orlando Duran — whose 18-year-old daughter, FIU student Alexa Duran, died in the collapse — said he watched the entire hearing, which was streamed online.
“I’m not happy, but I’m satisfied,” Duran said. “I sure hope the State Attorney’s Office is paying attention to see if there’s grounds to take this to the next level in terms of criminal charges.”
He is still waiting to hear from the university his daughter attended.
“FIU never reached out to us to say sorry. To say ‘Is there anything we can do to help out?’ “ Duran said. “My daughter was a student there, she studied political science. Her aspirations were to help the family by becoming a lawyer. That was truncated.”
In its probable cause finding, the NTSB said the collapse was caused by “the load and capacity calculation errors made by FIGG Bridge Engineers, Inc., (FIGG) in its design.” The agency added that an inadequate peer review of the design plans by engineering firm Louis Berger also contributed to the collapse.
The NTSB also cited “the failure of [general contractor] MCM; FIGG; [inspectors] Bolton, Perez & Associates Consulting Engineers; FIU; and the Florida Department of Transportation to cease bridge work when the structure cracking reached unacceptable levels and to take appropriate action to close SW 8th Street as necessary to protect public safety.”
During the hearing, the three board members of the federal investigative agency dismissed several counterclaims from FIGG arguing that the inquiry was flawed and had misidentified the cause of the collapse.
The NTSB — which cannot issue sanctions — released a summary Tuesday afternoon outlining the accident’s “probable cause,” as well as the board’s major findings and safety recommendations. A full report will be released in the next few weeks.
Among the NTSB’s safety recommendations are improved national design guidelines for concrete bridges, including their redundancy; having FDOT revise its processes for independent peer review and making it mandatory for roads to be shut when structural cracks are detected in bridges; and better training for FIGG engineers.
The immediate cause of the 1:47 p.m. collapse was workers tightening, or “retensioning,” 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 should have been independently reviewed, according to the NTSB.
“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 any of the five major parties behind the bridge 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.
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.
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 during the hearing
Serious cracks had started opening in the bridge weeks before the collapse — the result of FIGG’s 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.
Read the rest and see the pics here: https://www.miamiherald.com/news/local/community/miami-dade/article236483393.html