The National Transportation Safety Board (NTSB) released an investigative update (available to review and download below) to its May preliminary report on the March 15th collapse of a 174-foot-long pedestrian bridge linking the city of Sweetwater, Florida, with Florida International University over U.S. Highway 41. The FIU pedestrian bridge collapse killed five vehicle occupants and a bridge worker, and injured eight others.
The new NTSB update details examination of the bridge’s construction materials, which involved numerous tests of concrete compression core and steel samples. The six-page report includes new images that address areas of the steel post-tensioning rod and the hydraulic jack used during re-tensioning activities before the collapse.
According to NTSB, the investigators examined an approximately five-foot-wide section of the bridge deck that was cut on either side of Node #11 and #12. Steel post-tensioning rods from diagonal member 11 were involved in the re-tensioning activity that took place on the morning of the collapse.
While the update indicates there will be further testing on the hydraulic jack, the cracks do not yet explain the bridge’s collapse, according to NTSB:
The initial results from these tests and examinations have, thus far, not indicated any notable material issues,” the report concluded.
Review and download the report, with images:
Read our previous coverage of the FIU pedestrian bridge collapse: