A one-mile portion of the westbound lanes of Interstate 90 in Wisconsin could be closed for weeks after a bridge was damaged in an accident late Saturday morning.

Four of the five structural supports of the bridge, which carries I-90 traffic over Highway 35, were severely damaged at 10:41 a.m. when they were struck by a truck hauling a 75-ton piece of mining equipment, Wisconsin State Patrol Sgt. Frank Hefti said at the accident scene.

The bridge will be closed until at least Monday, but possibly much longer, while repair work is done, Hefti said. In the meantime, westbound traffic on I-90 has been rerouted to Highway 157 North to Main Street in Onalaska, then to Highway 35 South and back onto the interstate.

Hefti said the alternate route is temporary and the State Patrol and Department of Transportation hopes to restore two-way traffic by early this week, putting one lane in each direction on the eastbound lanes of I-90.

Highway 35 South was re-opened Saturday evening and should remain open until at least Monday, according to the State Patrol.

This is not the first time an oversize load has failed to clear that overpass: On Nov. 17, 2005, a truck pulling a construction end loader bent a steel bridge girder 4 to 5 inches. The bridge was not closed because there were no cracks or holes, and no injuries were reported.

In August that same year, a boat being towed on Highway 35 became stuck under the same overpass, holding up traffic for hours before it was freed by letting some air out of the trailer tires.

In Saturday’s accident, the truck driver started in Milwaukee but couldn’t go into Minnesota because his permit to haul an oversize load in that state did not become effective until today, Hefti said. Hefti did not know the truck’s final destination.

The driver got off at Exit 3 to Highway 35 south, heading south into La Crosse to find a place to stay the night, but the bridge wasn’t high enough for the load, Hefti said.

The drill bit caused “major structural damage to the bridge,” Hefti said, forcing the State Patrol to shut down I-90 from Exit 4 to Exit 3, so cars couldn’t drive on it, as well as Highway 35 from the interstate to George Street, so cars couldn’t drive under it.

While there were no injuries in the initial accident, it led to a secondary crash involving five vehicles, State Patrol Sgt. James Lind said Saturday afternoon. People were hurt in those accidents, but Lind was unsure of the severity of the injuries.

The effected portions of I-90 and Highway 35 were both closed or restricted for months last year for construction projects.

A $1.4 million Department of Transportation project on Highway 35 kept traffic restricted from summer through late fall as the intersection of Second Avenue and Oak Forest Drive was reconstructed. Work also was done to realign the intersection of Oak Forest Drive and Oak Avenue, and left-turn lanes and sidewalks were added.

During the same time, traffic on I-90 was shifted to a single lane in each direction near Exit 3 to widen bridges and replace decks over the Burlington Northern Santa Fe Railway. The $4 million project spanned from the Minnesota state line to state Highway 157.

Shortly after the bridge incident, the State Patrol reported another accident on westbound I-90 near Highway 157, involving several vehicles and a fuel spill. The State Patrol had no additional information Saturday evening.

Alternate routes

Interstate 90 will be closed from Exit 4 to Exit 3 until at least Monday. The State Patrol recommends this alternative route:

Take Exit 4 to Highway 157 North until Main Street in Onalaska.

Turn left onto Main Street, and stay on that to Highway 35 South.

Turn left onto Highway 35 South, and get back on I-90 at exit 3.

Highway 35 South, which is open until Monday, will close from the I-90 Exit 3 ramp to George Street. Enter I-90 West at Exit 3 and get off at Exit 2, then drive through the town of Campbell to get into La Crosse.

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