NTSB Blames Minn. Bridge Collapse On Gusset Plate Design Error
National Transportation Safety Board investigators said on Nov. 13 that the 2007 Minneapolis bridge collapse that killed 13 people and injured 145 others started when gusset plates on the upper side of steel deck truss fractured and that the plates failed due to a "design error."
At the first day of a two-day NTSB meeting to determine the probable cause of the accident and recommend safety improvements, Mark Bagnard, the leader of the NTSB team investigating the accident, said that plates at one "node" or connection-point on the upper edge of the steel deck truss "were unable to sustain the load experienced on the bridge." Bagnard said that the failure of those plates "resulted in the total collapse of the bridge."