Calculation Errors Caused The Collapse Of a Pedestrian Bridge In Florida That Left Six Dead

Miami – Calculation errors and lack of an independent review were the "probable cause" of the collapse in 2018 of a pedestrian bridge under construction in Miami that killed six people crushed in their vehicles, the National Security Board of Transportation (NTSB).

"Errors in the design of the bridge, inadequate peer review and poor engineering judgment led to the collapse of the bridge," said Robert Sumwalt, president of the NTSB.

During a public hearing, the federal agency also lamented the "failure" of the construction companies, the Florida Department of Transportation (FDOT) and the Florida International University (FIU) for not closing the road on which the bridge was built to traffic to "safeguard public safety."


The collapse of the viaduct, built using the "accelerated" method and which sought to connect FIU with the suburb of Sweetwater, also injured ten other people.

The NTSB criticized on Tuesday the load and capacity calculation failures by the construction companies FIGG Bridge Engineers, Inc. and Munilla Construction Management (MCM), but also the deficiencies at the time of the verifications by the independent consultants.

The "inadequate revision" by the Louis Berger Group, which did not detect FIGG calculation errors in its design, was added to FIGG's errors in anticipated cracking in the structures.

In addition, he noted that the independent firm Louis Berger "was not qualified by the Florida Department of Transportation to conduct an independent peer review," and said that state agency "should have verified Louis Berger's qualifications."

"The failure of all interested parties to recognize and act on the threat to public safety presented by the significant tension observed in the structure of the bridge before the collapse led to the tragic loss of life in this avoidable accident," Sumwalt said.

Early investigations revealed that one of the engineers at the design firm, FIGG Bridge Design, alerted a voice message to an employee of the Florida Department of Transportation (FDT) of the existence of a crack in the platform shortly before It sank.

But in the message, the expert said that, although "obviously" some "repairs" would have to be done, this did not compromise the structural integrity of the 950-ton and 174-foot-long (53 meter) footbridge.

The collapse of the bridge, which occurred in March 2018 in broad daylight, totally or partially impacted eight vehicles, seven of which were occupied.