An official cause of death has not been disclosed by authorities but TMZ speculates that the 21-year-old reality star along with his uncle David Gandee, and Donald Robert Myers died from carbon monoxide poisoning.

Shain was reported missing on Sunday and his friends launching a search for him. MTV reports that a friend found the three men in Shain's Ford Bronco which was partially submerged in mud.

Kanawha County Sheriff's Office released a statement to MTV that said Shain was in the driver's seat of the Bronco, and the vehicle's muffler was completely submerged in mud.

"Their bodies were removed from the vehicle and have been taken to the Office of the Medical Examiner," the statement reads. "Autopsies will be performed to determine the cause of death."