The Wisconsin Department of Transportation says an inspection that continues, has so far revealed that pilings located eight feet below the bottom of the concrete footing of the Leo Frigo Bridge, along Interstate 43 in Green Bay, buckled due to corrosion.
The span has been closed in both directions since September 25, after a section 400-foot-long was found to be sagging by around two-feet.
The investigation has also found that the vast majority of the other bridge piers being checked are in the same condition as they were when they were installed 33 years ago. The bridge has not moved since it settled and the department believes there is no danger of collapse.
The closure of the bridge has forced some 40,000 vehicles per day to use detour routes.
The state DOT has no estimate when the bridge might reopen.