INDIANOLA, Pa. — A natural gas well where welders were believed to be working exploded Friday, killing two people and sparking a fire that spewed black smoke for hours.
The blast happened around 9:50 a.m. in a remote, wooded area of Indiana Township, northeast of Pittsburgh, police said. Firefighters doused the resulting fire with foam, and part of the blaze was still burning about three hours after the explosion.
The cause wasn't yet known, but state officials believe "people were welding at the site and there was an explosion and the well caught fire," said Helen Humphries, a spokeswoman for the state Department of Environmental Protection.
"Why they were welding or what caused the explosion, I don't know yet," she said. A truck near the well had its paint scorched off and at least one of its tire had melted.
The well, dubbed Murray Heirs No. 6, is a shallow well, about 3,500 feet deep, and was drilled in May 2008, Humphries said. It was considered to be a producing well, she said.
The department won't be able to determine the environmental impact until after the fire is extinguished, Humphries said.
Travis Novak, a 16-year-old who lives about a half-mile away, said he was sleeping when he was woken up by the explosion. "Then I got up and looked and heard another wild explosion," he said.
The teenager and his friend Cory Drischler, 14, walked toward the site and saw "smoke just pouring out of the woods and then a loud bang. You could hear this loud noise like the gas was rushing down the hill."
The well is owned by Huntley & Huntley Inc., which operates 389 gas wells in the state, according to DEP figures, and is also active in Oklahoma. The Monroeville-based company confirmed its workers had arrived at the well, but a spokeswoman said she had no further information.
Humphries said the privately held firm does not have a record of violations.
The accident is the latest misfortune to strike the region's burgeoning natural gas industry.
Last month, a well in north-central Pennsylvania without proper pressure-control systems exploded as a crew was preparing to hook it up to a pipeline. No one was injured.
A few days later, seven people were injured in a rig explosion in West Virginia's Northern Panhandle when the drilling crew struck a pocket of methane gas while sinking a natural gas well through an abandoned coal mine.
In May, a worker at a Susquehanna County drilling site was killed when he was hit on the head by a pipe, a death that the coroner ruled an accident.
In northeastern Pennsylvania, state environmental officials have said construction flaws in gas wells were responsible for allowing gas to seep into the area's groundwater.
DEP Secretary John Hanger said in an e-mail message that the well where the accident occurred Friday is not part of the lucrative Marcellus Shale, a rock formation that drillers began tapping about two years ago.
As of 2007, Pennsylvania had more than 65,000 producing oil and gas wells, the vast majority of them drilled no deeper than 3,000 feet into the shallow sands underneath western Pennsylvania. The DEP estimates that as many as 350,000 wells have been drilled in the state going back to 1859.
Associated Press writer Marc Levy in Harrisburg, Pa., contributed to this report.