WASHINGTON (AP) — Slippery road conditions are being blamed in part for the death of a Machiasport man in a traffic accident.

The Knox County Sheriff’s Office said 83-year-old William Coperthwaite was driving his van south on Route 220 in Washington at about 12:30 p.m. Tuesday when his vehicle left the road, struck a large rock and then spun into a tree on the driver’s side.

Coperthwaite was pronounced dead at the scene.

He was alone and no other vehicles were involved.

The crash remains under investigation and police are looking into whether Coperthwaite had a medical emergency.