A 44-year-old man died early Saturday when his pickup truck caught fire in Richmond, according to the Maine State Police.

Jerry Kiesow of Richmond was found dead around 3:30 a.m. Saturday in his burning pickup truck along Lincoln Street, Maine Department of Public Safety spokesman Stephen McCausland said Sunday afternoon.

The Maine medical examiner’s office still is working to determine Kiesow’s cause of death, McCausland said.

The Maine fire marshal’s office, along with the Richmond Police Department, is investigating the incident, he said.