MEREDITH – Five firefighters were injured fighting a one-alarm fire in a downtown apartment house Saturday night that investigators say may have been caused by smoldering smoking materials.

Firefighters were called at 8:07 p.m. by several residents reporting a glow over the downtown area, said Deputy Fire Chief Andre Kloetz.

They found the fire just a few blocks away from the fire station at 12 Dover St. Flames were reaching out of the porch area of a second-floor apartment in the back of the 2-1/2-story, 125- to 150-year-old building, Kloetz said.

An initial report had someone trapped in the building, he said, but firefighters quickly determined that none of the seven to eight people living in the building's five apartments were home.

Crews from Meredith and six surrounding communities managed to knock down most of the flames in the back apartment within about 20 minutes, but the fire spread quickly through the building's attic above other apartments. The fire wasn't fully under control for more than an hour after the initial call, he said.

“It was an unusually brutal fire,” Kloetz said. “We had three firefighters down just from the heat.”

Three firefighters from Meredith had heat exhaustion and another sustained a broken nose while working on a stairway, he said. A Laconia firefighter sustained a minor head injury. All five were sent to Lakes Region General Hospital in Laconia for treatment and have been released, he said.

Only one alarm was needed as 29 call firefighters from the town's volunteer department responded. With the help of fire crews from Laconia, Center Harbor, Holderness, Moultonborough, New Hampton and Gilford, the building was not a complete loss, though Kloetz estimates that at least $200,000 worth of damage was done to the approximately 3,200-square-foot building.

“They did a fantastic job getting the fire knocked down quickly,” he said. “But once it got into the attic, it was a matter of tearing down ceilings (in other apartments) to stop it.”

Fire department investigators spent hours looking for the cause, Kloetz said. They believe the fire started on the back porch.

“We know that both occupants were smokers, and we are leaning toward improper disposal of smoking materials as the potential cause,” he said. “We've ruled out most everything else. There were no electrical issues found and no one was cooking at the time.”