THIS DAY IN HISTORY: On August 1, 2007, just after 6pm, the Interstate 35W bridge over the Mississippi River in downtown Minneapolis collapsed, taking down 111 vehicles on it during rush hour traffic. 13 people were killed and 145 others were injured. The bridge had been under construction at the time, but The National Transportation Safety Board determined that the probable cause of the collapse “was the inadequate load capacity, due to a design error of the gusset plates which failed that day