A South Lake Tahoe fire captain was killed in a snowmobile accident a mile south of the Blue Lakes Sno-Park on Tuesday evening.
Stephen David Taylor, 58, was riding with two friends when he struck a tree and was bleeding from the head.
The incident was reported to the Alpine County Sheriff's Office at 5:07 p.m., according to Lt. Ron Michitarian.
Taylor and two friends had been riding their snowmobiles all day and were on their way back to their vehicles.
Taylor was pronounced dead at the scene.
Michitarian said Alpine County is investigating Taylor's death while the California Highway Patrol is investigating the accident.
"Preliminary investigation indicates the accident may have been a result of an unknown medical episode," Michitarian said.
An autopsy and toxicological examination are pending in the case.