NEW DURHAM – An early morning three-alarm fire destroyed a former service station and convenience store, but caused no injuries.

Firefighters responded to 50 Main St. at 2 a.m. and crews arrived at the fire within a few minutes, according to Fire Chief Peter Varney.

Because the building had a metal roof, Varney said firefighters were unable to vent the fire. That concentrated the heat inside, making conditions very dangerous, he said.

“We did two interior attacks and were driven out,” Varney said. After firefighters got the fire under control at 4 a.m., they called in for an excavator to knock down the remains of the building.

Varney said local crews were assisted by firefighters from Alton, Barnstead, Farmington, Gilmanton, Middleton, Milton, Rochester, Wakefield and Wolfeboro. Barrington firefighters responded to provide station coverage during the incident, the chief said.

Varney said investigators have not determined the cause of the fire or whether it was suspicious or not.

“We’re still looking on it,” he said.

Firefighters closed a section of Main Street for most of the morning, except to let school buses through. The road was re-opened around 10:30 a.m.