A crashed semi-truck caused a shutdown of I-80 westbound between Laramie and Walcott Junction Wednesday.

Wyoming Highway Patrol says calls came in at about 8:30 a.m. reporting a semi had rolled over around mile marker 270 west of Arlington and was leaking a hazardous material.

Sgt. Jeremey Beck said Wednesday afternoon that the patrol was not yet aware of what the truck was carrying, but that a Laramie hazmat response team was on the scene effectively executing a clean-up of the area.

As of 8 a.m. Thursday, the Wyoming Department of Transportation estimated a re-opening of westbound lanes in 4 to 6 hours, saying that maintenance of the road surface was required.