NTSB Determines Inadequate Load Capacity Due To Design Errors Of Gusset Plates Caused I-35W Bridge Collapse

Monday, November 17, 2008

The National Transportation Safety Board (NTSB) has determined the probable cause of the collapse of the I-35W bridge in Minneapolis, Minnesota, was the inadequateload capacity of the gusset plates at the U10 nodes, which failed under a combination of (1) substantial increases in the weight of the bridge, which resulted from previous modifications, and (2) the traffic and concentrated construction loads on the bridge on the day of the accident.