I-35W Mississippi River bridge collapse (2007)
On August 1, 2007, the eight-lane I-35W bridge over the Mississippi River in Minneapolis collapsed during rush hour, killing 13 and injuring 145. Investigators found a design flaw in the bridge's steel gusset plates, compounded by corrosion and heavy loads.
The collapse triggered a national inspection of similar steel deck truss bridges and a roughly $250 million replacement, which opened in September 2008.
It became the benchmark for why aging bridge substructures and steel elements get prioritized for preventive repair.
The steel beam and substructure work on this Grand Rapids ramp is exactly the class of preventive maintenance the I-35W collapse pushed to the front of state transportation budgets.
