Firefighters from all five Newtown fire companies and Newtown Volunteer Ambulance Corps were sent to a King Street home early Sunday afternoon following multiple calls for a fire.

Hook & Ladder Volunteer Fire Company Chief Chris Ward, who served as the incident commander, said approximately 40 firefighters responded to 9 King Street for a reported garage fire after being dispatched at 12:57 pm.

“Upon arrival, we had moderate fire showing from the basement-garage area,” Ward said. The fire extended into a room above the garage. A Honda Accord in the driveway, to the immediate northeast of the house, also caught on fire.

King Street is a dead end off Castle Hill Road.

Ward said Tuesday afternoon that the first arriving firefighters found heavy smoke conditions on the first floor of the house. The first team of firefighters to enter the dwelling went in through the front door of the house with hoses, he said.

The homeowner was not home at the time of the fire.

Two dogs died during the incident. Two cats that were able to hide in an upstairs bedroom survived, according to the fire chief.

There were no injuries reported for any of the first responders.

The property is owned, according to the Town of Newtown online database, by John and Jennifer Humphreys. The house is a Colonial style single-family dwelling constructed in 1978, with 2,478 square feet of living space. Firefighters cleared from the property at 2:45 Sunday afternoon.

Fire Marshal Richard Frampton this week said that although the location where the fire started was confirmed, the cause was still unknown.

“It started in the garage,” he said Wednesday morning of the fire’s starting point. He had returned to the property with a fire investigator from the homeowner’s insurance company.

“The house is inhabitable,” Frampton said, adding that the garage and the room above it will “probably have to be torn down. The rest of the house had heavy smoke damage.”

In addition to firefighters from Hook & Ladder, Botsford, Dodgingtown, Hawleyville and Sandy Hook at the scene, standby coverage was provided by Brookfield at Hook & Ladder’s station; Stepney at Botsford’s firehouse; and Southbury at Sandy Hook’s main station.

Eversource was notified on Sunday of the fire. Damage restoration company JP Maguire was contacted for board-up of the damaged area of the home. The American Red Cross was also notified.