The St. Landry Parish Sheriff's Office says about 50 homes have been evacuated because of a railroad derailment.
The homes are within a mile of the spot where state police say at least 26 cars derailed about 3:30 p.m. Sunday, closing U.S. 190 east of Lawtell.
Master Trooper Daniel "Scott" Moreau says authorities have not reported any injuries, and the evacuation is a precaution.
He says some cars hold corrosive and flammable materials, including at least one flammable liquid.
Eastbound traffic is being diverted to Louisiana Highway 103. Westbound traffic is detoured to Louisiana Highway 104 and then to Highway 3043.
Lawtell is about 63 miles west of Baton Rouge and about 25 miles north-northwest of Lafayette.