The probable cause of the Florida International University pedestrian bridge collapse on March 15th, 2018, was load and capacity calculation errors by the bridge designers, according to a National Transportation Safety Board investigation.
The partially-constructed elevated foot bridge was being installed to improve pedestrian access across Southwest 8th Street, an eight-lane highway separating the FIU campus in University Park, a suburb west of Miami, Florida, and student housing neighbourhoods in the adjacent city of Sweetwater. During the days before the collapse, progressive cracking occurred in the post-tensioned concrete bridge, although its structural integrity was not thought to be compromised at the time.
On the afternoon of March 15th, re-tensioning of steel rods was underway when the structure catastrophically failed and the 950-ton, 174-foot span collapsed, crushing eight vehicles on the road below. One bridge worker and five vehicle occupants died, and ten other people were injured.
