<Tr> <Th_colspan="2"> Statistics </Th> </Tr> <Tr> <Th> Daily traffic </Th> <Td> 140,000 </Td> </Tr> <P> The I - 35W Mississippi River bridge (officially known as Bridge 9340) was an eight - lane, steel truss arch bridge that carried Interstate 35W across the Saint Anthony Falls of the Mississippi River in Minneapolis, Minnesota, United States . It had a catastrophic failure during the evening rush hour on August 1, 2007, killing 13 people and injuring 145 . The bridge opened in 1967 and was Minnesota's third busiest, carrying 140,000 vehicles daily . The NTSB cited a design flaw as the likely cause of the collapse, noting that a too - thin gusset plate ripped along a line of rivets, and additional weight on the bridge at the time contributed to the catastrophic failure . </P> <P> Help came immediately from mutual aid in the seven - county Minneapolis--Saint Paul metropolitan area and emergency response personnel, charities, and volunteers . Within a few days of the collapse, the Minnesota Department of Transportation (Mn / DOT) planned its replacement with the I - 35W Saint Anthony Falls Bridge . Construction was completed rapidly, and it opened on September 18, 2008 . </P>

When did the i-35 bridge collapse in minneapolis