‘Buckwild’ Star Shain Gandee Died From Carbon Monoxide Poisoning - Exclusive Pictures of his Bronco

Shain Gandee died doing what he loved.

While mudding with his uncle, David Gandee, and friend, Donald Robert Myers, following a night at a West Virginia bar on Saturday, the "Buckwild" star's 1984 Ford Bronco got stuck in the thick, dirty water and its tailpipe submerged, thus preventing the exhaust from leaving the car.

On Tuesday, the Kanawha County Sheriff's Department in West Virginia announced that completed autopsies confirmed: "The manner of death is accidental and the cause was carbon monoxide poisoning for all three subjects."

[Related: Shain Gandee Dead at 21: Who Was the 'Buckwild' Star?]

When Shain's truck was discovered early Monday morning, "The vehicle sat unevenly, but upright, and was partially submerged in deep mud," according to a statement from officials in Kanawha County, which led to speculation that carbon monoxide was to blame. "Mud was covering the lower part of the passenger side door of the vehicle, but the driver's side of the vehicle was above the mud. The muffler of the vehicle was completely below the surface of the mud."