The Medical Examiner's Office in Gainesville was unable to determine the identity of a man whose burned body was found in a truck in Macclenny on Saturday morning, according to the Baker County Sheriff's Office.

Firefighters were called to Robbie's Car and Truck Center at 136 W. Macclenny Ave. because a witness heard an explosion and a pickup truck was on fire behind the auto shop, investigators said. They said the explosion was likely a tire that popped from the heat of the flames.

When firefighters put the fire out, they found the man's body inside, investigators said. They said it was burned beyond recognition.

Dental records were inconclusive, and more forensic comparisons will be done Tuesday to try to identify the body.

It's believed the fire that killed the man was accidental.

Investigators said the body was found in an Isuzu pickup truck that had been sitting behind the repair shop for months. The place's owner, Robbie Kirkland, said he was waiting to make repairs to the truck. He said he didn't know why a man was inside.

"Maybe he crawled in there, fell asleep with a cigarette or something and caught fire, something like that," Kirkland said.

Baker County Sheriff Joey Dobson said there were no "physical signs of foul play."

The Florida Department of Law Enforcement has been brought in to help with the investigation.