Harrison County Coroner Gary Hargrove says Bernell Wilson, 40, was driving to work at the Dupont Plant in Delisle when the accident happened. Hargrove said Wilson was travelling westbound at a slow rate of speed with his flashers on.
An 18-wheeler driven by Ronnie Brown, 57, of Picayune, rear ended Wilson, a Highway Patrol spokesman said.
The collision sparked a fire that engulfed Wilson's car and the cab of the 18-wheeler.
Brown walked away from the crash without injury. Hargrove says an autopsy showed Wilson died from head and neck injuries and that he was already dead when the fire started.
The Highway Patrol listed the cause of the crash as Brown's "failure to yield," but did not issue any citations. A spokesman said the accident is still under investigation.