The National Transportation Safety Board (NTSB) offered an update on August 9 of its investigation of the March 15 collapse of a pedestrian bridge under construction in Miami.
As a result of the 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.
The update details the examinations of the bridge’s construction materials and notes the 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 examined an approximately 5-foot-wide section of the bridge deck that was cut on either side of what is referred to as node no. 11 and 12, which was photographed and subsequently documented using 3D laser scanning.
The NTSB says it 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.