A Buffalo, N.Y., truck driver whose rig crossed the median of Interstate 79 in Jackson Township on Sunday night suffered a fatal heart attack before the wreck, Deputy Coroner Bob Snyder said Monday.

Timothy T. Garlock Sr., 53, was headed northbound when he was stricken at about 10:40 p.m., about a half-mile north of the Mercer-Franklin exit, Snyder said.

Garlock's tractor-trailer crossed the median and the southbound lanes before coming to rest in a wooded area just off the west berm, Snyder said.

Garlock was taken to United Community Hospital, Pine Township, where Snyder pronounced him dead at 11:51 p.m. His body was sent to Erie for an autopsy, Snyder said.

State police were assisted by Jackson Center volunteer firefighters.