LANCASTER TWP — An accidental fire Sunday evening caused about $20,000 in damage to a house in the 500 block of Little Creek Road, authorities said.

No one was home at the two-story brick house about 5:25 p.m. when a neighbor spotted the fire and called 911.

Fire crews were able to rescue a dog inside the Lancaster Township house before quickly putting out the blaze.

It appeared the fire started in an addition to the older home in the area of the hot water tank, according to Brian Dambaugh, assistant chief with the Harmony Fire District.

Fire officials said the homeowner had been doing renovation work in the addition.

“Smoke was coming out of the roof area when we got there,” Dambaugh said.

An attack crew got inside and hit the blaze with compressed-air foam, gaining control of it in about 15 minutes.

“The fire was confined to the addition,” Dambaugh said, “but there was smoke damage to the main house.”

A couple and their infant child, who live there, returned home while firefighters were still on scene. The family’s name was not immediately available.

Damage was estimated at $15,000 to the structure and an additional $5,000 to its contents. The house was insured.

The family apparently is temporarily staying with relatives who live close but authorities said the house is habitable.

Volunteer firefighters from Evans City and Connoquenessing Towsnhip assisted the Harmony Fire District. All crews were back at their stations by 7 p.m.