Collapse of I-35W Bridge

Date: August 1, 2007 • Location: Minneapolis, United States

Bridge 9340, carrying Interstate 35W across the Mississippi River in Minneapolis, United States, suffered a catastrophic failure and collapsed (aftermath pictured), killing 13 people and injuring 145 others.

The I-35W Mississippi River bridge was an eight-lane, steel truss arch bridge that carried Interstate 35W across the Mississippi River one-half mile downstream from the Saint Anthony Falls in Minneapolis, Minnesota, United States. The bridge opened in 1967, and was Minnesota's third busiest, carrying 140,000 vehicles daily. After 39 years in service, it experienced a catastrophic failure during the evening rush hour on August 1, 2007, killing 13 people and injuring 145. The National Transportation Safety Board (NTSB) cited a design flaw as the likely cause of the collapse, noting that an excessively thin gusset plate ripped along a line of rivets. The amount of weight on the bridge at the time of failure was also cited by the NTSB as a contributing factor.