Authorities say two people died and a third was injured when an 18-wheeler in which they were riding ran off Interstate 12 near Lacombe, struck a tree and caught fire.
State police tell The Times-Picayune the injured person was taken to the Interim LSU Public Hospital in New Orleans with serious injuries.
Identities of the victims were not immediately released.
The tractor-trailer rig ran off the highway's eastbound lanes near the Lacombe exit in St. Tammany Parish.
Traffic backed up in both directions on the highway as police and firefighters worked at the scene.