TRENTON – The cause of a fatal accident Monday in which an Ellsworth woman was found unresponsive in her vehicle is still under investigation, according to police.

Police believe the woman may have gone off the road because of a medical condition, Hancock County Deputy Sheriff Jason Lepper said Tuesday.

Debby Stormann, 46, was driving a 1999 Chevrolet pickup truck east on Route 204 at 11:15 a.m. Memorial Day when the vehicle and the horse trailer it was towing drifted into a guardrail off the right side of the road, Lepper said. The vehicle then sideswiped a utility pole before coming to rest on a nearby golf course.

By the time witnesses reached the vehicle, Stormann was unresponsive, he said. She was taken by ambulance to Maine Coast Memorial Hospital in Ellsworth, where she was declared dead.

Stormann was alone in the truck, and no other vehicles were involved in the accident, Lepper said.

The horse in the trailer was not injured in the accident, he said. The truck had about $5,000 in damage.

Police expect to hear back in a few days from the state medical examiner’s office about how Stormann died, according to the deputy. He said there were no visible signs of injury to Stormann as a result of the accident.