Washington, D.C. — The National Transportation Safety Board (NTSB) issued an investigative update on the ongoing investigation of the collapse of a pedestrian bridge under construction in Miami. As a result of the March 15 structural failure, a 174-foot-long bridge span fell about 18.5 feet, killing five vehicle occupants and a bridge worker. Eight other people were injured.
This photo illustrates the condition of the cracks after the move of the main span that occurred on March 10, 2018. Photo taken on March 14, 2018 at 1:50 pm shows east side directly adjacent to vertical member 12, top of deck looking down, view of crack. Labels added to photo by the NTSB. (Photo: Bolton, Perez & Associates Consulting Engineers)
The update details the thorough examinations of the bridge’s construction materials and notes numerous tests conducted including multiple concrete compression core and steel sample tests. The investigative update also includes an evaluation of a steel post-tensioning rod and the hydraulic jack used during the re-tensioning activity before the collapse.
NTSB investigators and parties to the investigation examined an approximately 5-foot-wide section of the bridge deck that was cut on either side of Node #11 and 12, which was photographed and subsequently documented using 3D laser scanning.
Currently, the NTSB has interviewed employees from eight firms and organizations involved in the design, inspection and construction of the bridge.
Bolton, Perez & Associates Consulting Engineers has been added as a party to the investigation.
All aspects of the collapse remain under investigation while the NTSB determines the probable cause, with the intent of issuing safety recommendations to prevent similar events.