The long, deep dip was discovered Wednesday, but officials say the Leo Frigo Memorial Bridge isn't in danger of collapsing.
The bridge that carries Interstate 43 over the Fox River in Green Bay, Wis., will remain closed indefinitely after a concrete support pier settled by more than two feet.
Officials closed the Leo Frigo Memorial Bridge early Wednesday when a long, deep dip was discovered in the pavement about 5 a.m.
Gov. Scott Walker said the state will fix the bridge, emphasizing its importance to northwestern Wisconsin's economy.
State Transportation Secretary Mark Gottlieb said the bridge is not in danger of collapsing. But Kim Rudat, the DOT's Northeast Region spokesman, said the closure could last months or even a year.
The bridge, built in 1981, carries about 40,000 vehicles a day. It passed an inspection in August 2012, the Green Bay Press-Gazette reported.
The bridge was previously known as the Tower Drive Bridge before it was renamed in 2011 in honor of the Green Bay-area civic leader and philanthropist.
Viewers of The Oprah Winfrey Show may have seen the bridge when guest Tina Zahn described her July 2004 suicide attempt. Her rescue by a Wisconsin State Patrol trooper was recorded by a squad car's dashcam.