Designers miscalculated load-bearing strength of collapsed FIU bridge

Cracks in the bridge were consistent with the design errors, but an ongoing investigation by the National Transportation Safety Board is expected to continue into next year

FIU pedestrian bridge collapsed March 15, killing six people (Credit: CNN)
FIU pedestrian bridge collapsed March 15, killing six people (Credit: CNN)

Designers miscalculated the load-bearing strength of the north end of the Florida International University pedestrian bridge that collapsed and caused six deaths, according to federal investigators.

In an update on the federal investigation of the deadly March 15 collapse, experts from the Federal Highway Administration also reported Thursday that designers miscalculated the structural load on the north end of the FIU bridge.

The design errors were consistent with cracks in the FIU bridge before it collapsed, according to the investigative update.

However, the National Transportation Safety Board didn’t cite those design errors as the cause of the bridge collapse, and its investigation of the catastrophe is expected to continue into next year.

Federal Highway Administration experts determined that designers underestimated of the structural load on the north end of the FIU bridge and overestimated the load-bearing strength “of that same critical section.”

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Two days before the collapse, an engineer with FIGG Bridge Group, the firm that designed the FIU bridge, left a telephone message with officials at the Florida Department of Transportation (FDOT) to report cracks in the bridge and to convey the firm’s belief that the cracks didn’t indicate a safety issue.

FDOT officials didn’t hear the telephone message until after the bridge collapsed.

According to the university, FDOT attended a meeting to discuss the cracks just hours before the bridge collapsed.

In a statement, FIGG said the investigative update didn’t determine the cause of the collapse and the firm continues to work with the National Transportation Safety Board. [Associated Press]Mike Seemuth