NEW MILFORD — A family came back to their Candlewood Road North home Saturday night to find it on fire, a blaze that would consume the house and call in fire departments from surrounding towns for about five hours.

“It was a fully involved structure fire, single-family home,” said Chief James Ferlow of New Milford’s volunteer Water Witch Hose Company No. 2.

He said crews were called to the single-story home at 457 Candlewood Road North at 6:51 p.m. They were able to bring the blaze under control by about 9:45 p.m.

“The house is a total loss,” said Kevin Reynolds, the city’s deputy fire marshal. He said investigators believe the fire started on the main level of the one-story home, which has an attic, but the cause of the blaze has not yet been determined.

Two middle-aged adults were displaced by the fire, the deputy fire marshal said.

“They seemed in as good a spirits as they could for their house burning down,” said Reynolds. The family did not have any pets in their house, and did not have children living with them.

The Red Cross has been assisting the couple, and New Milford residents have begun organizing a drive to help them through Facebook.

Firefighters from the Gaylordsville and Northville neighborhoods of New Milford as well as the nearby town of Brookfield were called in to help.

“When you have a fully-involved structure fire, you call for backup — you can always send them back,” said Ferlow.

All told, six tanker trucks and five engines carrying firefighters were sent to the scene. Fire companies from four other towns nearby were placed on standby in case another call came in while New Milford’s firemen were tied up at the house.

Eversource was called and disconnected power to the house, Reynolds said.

The chief said crews fought the fire from the outside of the structure, and did not go inside.

One Water Witch firefighter was hurt after he slipped on the ice and broke his ankle, the night’s only reported injury, officials said.

After the blaze was put out, firefighters stayed at the house for a few hours to clean up, Ferlow said. The public works department was called to handle icing from water used to fight the fire.

Investigators are still determining what caused the fire. The fire marshal’s office could not immediately be reached Sunday morning.

Property records show the two-bedroom home, built in 1968, was last sold in 2006 for $337,000.