Investigators were at the scene of a house fire in Saco on Wednesday, trying to determine what started the early-morning fire that badly damaged a two-story home on Maple Street.

Nobody was hurt but the fire extensively damaged the building, said Fire Chief John Duross.

A couple and their three young children were displaced by the fire. The family reported the after they were woken up by a loud “bang,” Duross said. He hopes investigators can determine the source of the noise.

The fire, at 44 Maple St., was reported at 1:20 a.m. and the first fire crew arrived at 1:25 a.m. The fire was under control at about 3 a.m.

“I have nothing but high praise for the first firefighters on the scene,” Duross said. “The volume of fire that was there on arrival was as big as we’ve seen in Saco for some time. They did one heck of a job keeping the damage to what was there.”

There was heavy fire at the back of the building when crews arrived and there was a danger it would spread to the house next door, about 20 feet away. There was ultimately some exterior damage to that building.

“Winter in Maine caused us some problems – snow, ice, cold, wind,” Duross said. “We were dealing with snowbanks, trying to drag lines out back of the building. We bring water which creates some ice. There were no injuries. There were some slips.”

Duross said firefighters could not hear any smoke detectors going off when they arrived but investigators will take a more in-depth look into whether the building had detectors.

The family got out OK as did the family dog, he said. Two bearded dragons, a species of small lizard, were found safe inside their glass enclosures inside the house.

Duross said the house is “not livable at this time.”

Crews from Biddeford, Old Orchard Beach and Goodwins Mills also responded to the fire.

City tax records say the house was built in 1900 and the building is worth about $92,400.