Photo courtesy of San Sebastian County S.O.

Photo courtesy of San Sebastian County S.O.

A veteran Sebastian County (Ark.) Sheriff's deputy died after his patrol car flipped into a ditch along Highway 96 in Lavaca early Saturday, the agency announced.

Corporal Terry Johnson, who served the agency for 16 years, was taken by rescue personnel to Mercy Hospital shortly after the 4:20 a.m. crash. The 48-year-old deputy was pronounced dead at 12:42 p.m. A citizen had called 911 to report an overturned patrol unit.

Corporal Johnson's body has been sent to the state's crime lab and the Arkansas State Patrol has taken over the investigation. Investigators believe the deputy lost control of his vehicle following a medical episode, an agency spokesman told POLICE.

Johnson had been promoted to patrol supervisor in January 2012, after rising up the ranks in the sheriff's detention unit. The agency's last line-of-duty death came in 1997, when Deputy Ronald Kanz died in a vehicle crash. The sheriff's office's 40 road deputies patrol Arkansas' fourth-largest county with about 130,000 residents.