PETERBOROUGH, N.H. (AP) - Investigators say an explosion in a New Hampshire factory likely started in a room where acid is used to treat the surface of ball bearings.
Monday's explosion at New Hampshire Ball Bearings Inc. blew out windows, shook walls and sent more than a dozen people to the hospital. Deputy Fire Marshal Max Schultz says investigators are focusing on the company's "acid room," but it could be weeks before they determine the exact cause.
All but two of the injured workers were released from the hospital Monday. Schultz said none were close to the blast, which happened shortly after a shift change.
The plant in the southwestern New Hampshire town of Peterborough manufactures parts for the aerospace industry. A company official said he didn't know when its 700 employees would return to work.
THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.
First responders are working to determine what caused an explosion at a ball bearings plant that shattered windows, shook walls and sent at least 15 people to the hospital.
Monday afternoon's blast at the New Hampshire Ball Bearings Inc. plant in Peterborough is being investigated but all indications were that it was an industrial-related incident, said Peterborough Fire Department spokesman Eric Bowman. There didn't appear to be any environmental damage.
Plant machine operator Paul Clark said he was outside in the parking lot when he heard the explosion.
"I was in my car backing out when I felt a rumble and heard a bang," he said. "I looked up, and snow on the building's roof was flying into the wind."
The plant, in the southwest New Hampshire town that was the inspiration for Thornton Wilder's play "Our Town," manufactures high-tech parts for the aerospace industry and employs 700 people. Company spokeswoman Kathy Gerrity said she wasn't sure how many people were inside when the explosion happened but there are usually about 450 working around that time.
The blast blew out windows on the three-story building's ground floor, and the first arriving firefighters saw a column of smoke, said Bowman.
Clark, who operates a machine used in a rolling procedure, said his girlfriend, Andrea Painchaud, was at work in the shipping department when the explosion knocked shelves off the walls and part of the roof came down around her. He said she was uninjured.
"Smoke came pouring out," said Clark, who lives in nearby Pepperell, Mass. "I could hear somebody screaming."
Bill Brock, owner of the Manhattan East Hair Design shop about a quarter-mile from the plant, said he heard and felt something but didn't know what it was. Then about 30 ambulances and fire trucks went by.
Gov. Maggie Hassan said the state emergency operations center was open to monitor the situation and she was "very encouraged" to hear that all employees had been accounted for.
"My thoughts and prayers go out to those injured in today's explosion, to their families and loved ones, and to the entire Peterborough area where NH Ball Bearings is such an important member of the community," she said in a statement.
Two of the 15 people injured were treated at Monadnock Community Hospital and later were flown to other hospitals, spokeswoman Laura Gingras said. The rest were released by Monday night.
Bowman said in a news release that two people had suffered critical injuries.
Peterborough has about 6,400 residents. Besides inspiring "Our Town," a Pulitzer Prize-winning play first performed in 1938, it is home to the MacDowell Colony, a prestigious retreat for artists, writers and composers. Wilder based the fictional town of Grover's Corners on Peterborough, where he often spent his summers.
New Hampshire Ball Bearings' corporate headquarters are in Chatsworth, Calif. It's a division of Japanese company Minebea.
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