Authorities say two teens were killed when an oil tank they were jumping on exploded and hurled them 150 yards.
Rio Blanco County Undersheriff Michael Joos said the teens were killed Saturday night at a party in the Routt National Forest about 135 miles west of Denver.
The victims were identified as 17-year-old Samuel Hedemark of Phippsburg and 19-year-old Christopher King Fuller of Yampa.
Joos says vapor from the 160 barrels of crude oil in the tank may have been forced out through a relief valve by the pressure of the teens jumping on the top.
He says deputies were investigating whether a campfire or a cigarette lighter may have ignited the vapor.
Joos said some of the 18 people at the party had lit a campfire but he's not sure how close it was to the tank.
He says alcohol was a factor but he did not elaborate. A call to the coroner's office was not answered.
Joos says a dog was also killed in the explosion, but no other injuries were reported.
The Colorado Bureau of Investigation is also investigating.