PRAIRIE DU CHIEN, Wis. (AP) -- The state is barring overweight commercial vehicles from a bridge over the Mississippi in Prairie du Chien.

Officials made the decision to post weight limits after workers doing repairs on the bridge heard a noise.

That's according to Sgt. Jeramy Foster of the Tomah Post of the Wisconsin State Patrol.

He says they're now investigating and will determine if they need to take more action.

The bridge on Highway 18 is open to normal traffic but commercial vehicles are being limited to 80,000 pounds. That's the normal maximum load limit for most of the state's highway system.

Trucks with overweight permits are being rerouted in Dubuque, Iowa.

The two-lane, tied-arch bridge was built in 1974.

(Copyright 2008 by The Associated Press. All Rights Reserved.)