[chris]

The eight-lane I-35W Mississippi River bridge, officially Bridge 9340, collapsed during the evening rush hour in Minneapolis, Minnesota, on August 1, 2007. The steel truss arch bridge had opened in 1967 and carried about 140,000 vehicles a day.

Thirteen people were killed and 145 were injured. A school bus was among the vehicles caught in the collapse.

The NTSB cited a design flaw involving undersized gusset plates that ruptured along a line of rivets. Additional weight on the bridge at the time contributed to the failure.