This bridge connect downtown Minneapolis to the north. St. Paul and Minneapolis are connected via I94, running east-west.
As Andrew stated, they are looking for someone/something to blame. Terrorism has been ruled out.
Bridge did pass state safety inspections in 2005 and 2006. There was a federal test done in 2001 that noted some structural deficiencies. Also in 2001, the U of MN engineering department performed stress tests on the bridge. Some metal fatigue was noted, but nothing significant. Bridge was rated as safe for another 20 years.
Good thing that there was the maintenance being performed on the bridge (concrete roadway repair, nothing structural). That limited the traffic to 10mph and only 1 lane each way, down from 65mph with 4 lanes each way. At that time of day, all 8 lanes would have been packed, with commuters heading home (north bound) and Twins fans heading to the game (south bound).
The Minneapolis commute will not be fun for many a year.
I'm glad I have no reason to travel that part of the Twin City freeway.