A neighbor found the body of Andrew Piekarski, 61. He had last been seen several days earlier.

Investigators determined that Piekarski drove off a small hill, and the lawnmower landed on his legs. When Piekarski could not free himself, he unsuccessfully tried to take the lawnmower apart using a multipurpose tool, authorities said.

“He couldn’t get if off his legs and he couldn’t get out from under it and he died from exposure, from hypothermia,” Alaska State Troopers spokesman Greg Wilkinson said.

At the time of his death in mid-September, overnight low temperatures at Talkeetna, about 80 miles north of Anchorage, had been dipping into the 30s.