PLAQUEMINE, La. (AP) – A Mississippi man has died after his truck ran off the road and underneath the Atchafalaya Basin Bridge in Louisiana.

Shortly before 7:30 a.m. Monday, Louisiana State Police began investigating a single-vehicle crash on Interstate 10 westbound at the Whiskey Bay exit in Iberville Parish.

WAFB-TV reports 50-year-old John Cloninger, of Pearl, died in the crash. Troopers say Cloninger was driving a 2001 Peterbilt tractor-trailer westbound on I-10. For reasons still under investigation, authorities say Cloninger ran off the road to the right and struck a concrete bridge rail. After hitting the railing, the truck fell to the ground underneath the bridge.

Cloninger, who was not wearing a seatbelt, was pronounced dead at the scene.

The crash remains under investigation.