A Vassalboro man died Friday night after he crashed an all-terrain vehicle in his yard, authorities say.

Maine Game Wardens were called to the Kennebec County town around 8 p.m. after a passing motorist spotted the ATV on its side, lying on top of a man, and called 911, according to Mark Latti, a spokesperson for the Maine Department of Inland Fisheries & Wildlife.

Maine State Police and EMS lifted the ATV off the man, who was pronounced dead at the scene; he was identified as 52-year-old Cobey Schmidt.

Latti said investigators determined that Schmidt was driving the side-by-side ATV on his property when the vehicle’s left front tire hit a rock. Schmidt, who was the only person in the vehicle, was partially thrown from the ATV, which then rolled on top of him.

Investigators believe speed was a factor in the crash, Latti said.