College students holding a party in the Utah ghost town of Grafton are believed responsible for a fire that destroyed a movie set home used by actors Paul Newman and Robert Redford, investigators said.

The so-called Butch Cassidy House, constructed for the 1968 film Butch Cassidy and the Sundance Kid, was destroyed by a fire built in a fake fireplace, Washington County Sheriff Glenwood Humphries said Wednesday."We don't think it was arson," said Humphries. "We're investigating it as vandalism. The fireplace was a plaster dummy, and the fire spread through the wooden house."

Tourists camping in the remote area 300 miles south of Salt Lake City told deputies they heard party sounds coming from the building Saturday. When they heard vehicles leaving, they came out of their tent and saw the house was on fire.

Springdale Fire Chief Albert Winsor said the ghost town on the southern bank of the Virgin River "is all private property open to the public through the generosity of the owners.

"If vandalism and destruction continue, these buildings may have to be closed. They're for sightseeing only."