BRENTWOOD, N.H. — A four-alarm fire tore through Brentwood Power Equipment Center Monday night, just moments after the owner had closed down for the night.

The blaze that began shortly before 6:30 p.m. gutted the business at 244 Route 125, which was rebuilt after a similar fire struck in 1999.

Owner David Flagg said he had just left the business and was walking over to his home next door when he heard a bang followed by the alarm sounding.

"I did a walk around. The lights were off. Everything was off. I came over here and I heard a pop," he said.

Flagg said he has no idea how the fire started.

"We had devices. We had safety stuff. We made sure everything is kosher and everything is the way it's supposed to be done," he said.

No injuries were reported.

The business, which has about eight employees, opened in 1986 and sells lawn and other power equipment. It also has a repair shop.

Flagg said he plans to rebuild.

"What else have I got to do? I have no choice, it looks like," he said.

Brentwood Fire Chief Joseph Bird said that when he arrived there was heavy fire in the garage area, working its way into the front of the business. He said it appears the fire started in the repair shop.

Getting water to the scene was a challenge, Bird said.

"It's a pretty wide-open building so it was a defensive attack to start with. It was going to stay a defensive attack. There was no way I was going to put anybody in there," Bird said.

Bird recalled responding to the fire in 1999.

"When I came around the corner I pretty much went, 'Here we go again,'" he said.