Doomed design led to FIU bridge collapse

A doomed design was the “probable cause” of the horrific collapse of a pedestrian bridge in Miami last year that killed six people and injured 10, the National Transportation Safety Board said Tuesday.

The 174- foot- bridge section, designed to connect Florida International University with the city of Sweetwater, was under construction on March 15, 2018, when it crashed to the road below.

A peer review that failed to detect the calculation errors by designer FIGG Bridge Engineers – and an engineer’s failure to recognize the importance of cracking before the collapse – contributed, the board said.

“FIGG Bridge Engineers severely underestimated the demand on the bridge, significantly overestimated the bridge’s capacity ... among other calculation errors,” NTSB Chairman Robert Sumwalt said. “But another structure failed in this accident, the structure of public safety oversight.”

NTSB staffer Dan Walsh said the construction was “high- risk” because of the complex design of the bridge. But he added that the school was overseeing the project, and the state Transportation Department was not required to have an inspector on site.

A full report will be published in about three weeks.

The company took issue with the findings. “At the NTSB meeting today, it was evident that the investigation into the FIU pedestrian bridge construction accident presented challenges for the agency to accurately understand all of the technical and factual components,” FIGG said in a statement. “The accident was the result of a complex series of events and failings by parties at multiple stages of the project.”