NTSB: Miami Bridge Collapse Due to Design Errors, Lack of Oversight

A Miami university bridge that collapsed and killed six people last year showed design errors and should have been more carefully monitored by the state government because of the project’s complexity, federal officials said.

The National Transportation Safety Board members concluded that the design firm FIGG Bridge Engineers Inc. underestimated the load of the bridge and overestimated its strength in a critical section that splintered, dropping a 174-foot-long span onto eight cars on March 15, 2018.

NTSB’s chairman Robert Sumwalt said the cracking observed days before the collapse should have prompted contractors and the Florida International University to close the road. The engineers investigating the collapse told the board members the cracks were 40 times larger than what is commonly accepted.

FIGG maintained that the bridge would not have collapsed if a critical section had been built according to state standards. But the NTSB findings said the bridge could still have failed because of design miscalculations. Designed to look like a cable-stayed bridge, the project was uncommon in that it was constructed with concrete rather than steel as similar bridges are, engineers said. The project’s complexity required greater oversight than was given by the Florida Department of Transportation, the board said in its findings.

The 19-month investigation concluded the company that had been tasked to conduct an independent review and spot potential design errors was mistakenly listed as qualified by the state transportation department. Transportation department officials said the builders shouldn’t have relied on its website-generated report as proof of credentials, but NTSB’s vice chairman Bruce Landsberg said the state should have paid more attention. The bridge collapsed immediately after crews tightened support rods in the northern section of the bridge.

The university said it intends to build a new bridge where the victims will be memorialized.