JEFFERSON -- The driver of a tractor trailer that crashed on North Clary Road Wednesday died of a medical condition.

Harvey L. Perkins, 62, of Whitefield, died of heart disease and not as a result of injuries sustained during the crash, a spokesperson for the State Medical Examiner's Office said Thursday.

The crash occurred around 8:15 a.m., as Perkins was driving his 2001 Mack truck north. The truck veered across the southbound travel lane and into a ditch before coming to rest on the driver's side.

Perkins, who was not wearing a seatbelt, was behind the wheel and unresponsive when responders arrived, said Lt. Rand Maker of the Lincoln County Sheriff's Department.

No other vehicles were involved in the crash.

North Clary Road, which runs between Routes 126 and 32, was closed for six hours as police investigated.

No hazardous materials escaped as a result of the accident, Maker said.