DUPLIN COUNTY -

The driver of an 18-wheeler may have fallen asleep when he crashed, killing him and critically injuring his passenger, investigators said.

According to the Highway Patrol, the wreck was near mile marker 367 on I-40, not far from Warsaw in Duplin County. It happened some time between 9:30 p.m. and 10 p.m. Saturday.

Troopers said 53-year-old Ronnie Carter, of Harrells, was killed after the tractor-trailer he was driving left the roadway and crashed. Carter may have fallen asleep at the wheel, said investigators.

At last check, Carter's passenger, 67-year-old John Mueller, also of Harrells, was in critical condition at New Hanover Regional Medical Center in Wilmington, troopers said.

There is no word on what caused the driver to crash, but troopers said neither speeding nor alcohol appeared to be factors.

The N.C. Department of Transportation said left lanes on both sides of the interstate where the wreck happened were closed until about 6 a.m. Sunday morning.