CHARLESTON, W.Va. -- Carbon monoxide poisoning killed "Buckwild" star Shain Gandee and two others early Monday, preliminary autopsy results indicate.Cpl. Brian Humphreys, of the Kanawha County Sheriff's Department, said partial autopsy results indicated that Gandee, 21, his uncle David Gandee, 48, and Donald Robert Myers, 27, all died of carbon monoxide poisoning in the cab of Shain Gandee's Ford Bronco. The vehicle was found stuck in mud off a trail near Thaxton Hollow in Sissonville.Humphreys said the Bronco was found partially sunk in the mud, with the muffler and tailpipe below the surface. Gandee was last seen at a bar about 3 a.m. Sunday, when he said he was going to go four-wheeling.Humphreys said the deaths were apparently accidental.Family members spent most of Sunday searching for the men before calling 911 to report them missing. Humphreys said Monday evening that one of Shain Gandee's friends found the truck and the bodies. Shain Gandee was in the driver's seat, Humphreys said.Rescuers had to use a bulldozer to remove the truck.Filming for the second season of the reality show "Buckwild" had begun recently. MTV representatives did not return requests for comment from The Charleston Gazette. MTV spokesman Jake Urbanski told The Associated Press that shooting for the second season was suspended Monday afternoon.Reach Rusty Marks at firstname.lastname@example.org or 304-348-1215.