It was unclear whether anyone at the MDM Muzzleloader building was hurt in the blasts, which started just after 1 p.m. and continued for at least two hours as ammunition exploded, said Mia West, the town's public information officer.
"Up until maybe 15 minutes ago the firefighters were still unable to get close enough because the ammunition was still going off in the building, but they have now calmed down the flames," West said around mid-afternoon.
About 40 nearby homes were evacuated, and some residents reported hearing the explosion up to a mile and a half away, West said. A shelter was being set up at the town offices.
"We did hear two distinct bangs," said Karen Ladd, editor and publisher of The News and Sentinel newspaper in Colebrook. She thought something had hit the roof of their building. "It knocked a picture off of my wall, right next to my desk. I will admit I panicked and I said, 'Get out!"'
Several communities in New Hampshire and Vermont sent fire crews.
"It's just major, major explosions and black powder," said Mishel Fenn, a bartender at the Colebrook House motel, who felt the blast two blocks away. "It shook the building, and I'm in a large building."
According to a report in a January issue of The Colebrook Chronicle, a weekly newspaper, a worker at the plant suffered serious injuries to his face and wrist when he a machine that processes gunpowder flashed in his face. That fire was put out quickly.
