A Minnesota man is dead after a commercial truck rolled on Interstate 80 in southern Wyoming earlier this week.

The man who died, 60-year-old Robert Petersen, was not wearing his seatbelt, according to a crash report from the Wyoming Highway Patrol. Troopers are investigating the possibility that the driver was fatigued or asleep as a contributing factor in the wreck.

The crash occurred near Elk Mountain at roughly 4:30 a.m. Wednesday. Petersen was a passenger in the truck when it drove off the pavement into the median near mile marker 276.

The driver overcorrected, causing the combination unit to roll onto the driver's side.

The road surface was dry and weather was clear at the time of the crash.