An autopsy on Shain Gandee, a cast member of MTV reality show "Buckwild," showed he died from carbon monoxide poisoning, Kanawha County Sheriff's Department said on Tuesday.
Deputy Brian Humphreys told Reuters that the deaths of Gandee, 21, his uncle David, 48, and friend Donald Robert Myers, 27, on Monday morning were ruled "accidental" after coroners completed autopsies on all three men.
Gandee was found dead in the driver's seat of his Ford Bronco pick-up truck in Sissonville, in Kanawha County, a rural West Virginia community.
The truck was found by one of Gandee's friends after the MTV star was reported missing by family members following a late-night session in a local bar.
Gandee's truck was partially submerged in a mud pit, and the vehicle's exhaust pipe was below the surface of the mud, the sheriff's department said in a news release.
MTV said in a statement on Monday that it was "shocked and saddened" by Gandee's death. A spokesperson told Reuters that the network had suspended production on "Buckwild."
Gandee was one of the lead cast members of "Buckwild," which follows a group of young adults living in rural West Virginia and has attracted some criticism for its portrayal of the cast's hard-partying ways.
Gandee was often seen on the show "four-wheeling" in his truck, driving through makeshift courses on off-road terrain, and "mudding," where he would drive at high speeds through mud pits.