Agents from the federal Bureau of Alcohol, Tobacco and Firearms arrived at the Blue Mountain Christian Retreat Thursday, along with two state fire marshals and a dog trained to track accelerants.

But as of late in the evening, no cause had been determined for the fire that destroyed the retreat's conference center, said West Penn Fire Co. No. 1 Chief Leroy Breiner.Breiner said ATF has been called in to investigate any fires involving places of worship. The federal agency became involved after several churches in the south had been deliberately burned, most of them in Texas.The center housed a non-denominational worship auditorium that seated over 400 people, a kitchen/dining area and offices.The fire started at about 2:45 a.m. Thursday. Breiner said a young man in one of the cottages awoke early to write in his journal and heard a loud popping sound. He looked out, saw the building ablaze, yelled for anyone in there to get out and called 911. No one was hurt in the fire, which began in the west end of the building.Another person, a woman, also called the emergency number, Breiner said.The building was completely engulfed when the first responders arrived.Firefighters from more than a dozen companies fought the blaze, then stayed throughout the day to make sure it was out. Firefighters did return to the scene in the early evening.They saved an adjacent book store/gift shop that sits about 20 feet from the conference center.The retreat, opened in 1974 by Chris Dornbierer and his late wife, Margaret, draws believers from surrounding states who come to worship, enjoy the quiet serenity of the retreat's 370 wooded acres and to listen to renowned preachers