Working smoke alarms are being credited with alerting the occupants to a fire in their home early Sunday morning.

The Hamilton Fire Department responded to a report of a fire at 2662 Dunmark Rd. in Ancaster at approximately 3:43 a.m. Upon arrival, firefighters found the four occupants outside of the house and confirmed a well-involved fire with flames showing from the back of the one-storey detached house.

Crews entered the home but were forced to withdraw due the amount of fire and structural instability of the roof. Shortly after firefighters withdrew, a portion of the roof collapsed. Fire crews initiated a defensive attack, and due to the heavy volume of fire encountered, a multiple alarm was dispatched to bring additional resources to the scene.

Damage to the home is extensive and has been estimated at approximately $750,000. The cause of the fire has not yet been determined, however, it is not considered suspicious. Due to the high dollar loss, the Office of the Fire Marshal has been notified of this fire. There were no injuries.

The occupants have made arrangements for alternate accommodation as the home is inhabitable.

Claudio Mostacci, public information officer, said the fire highlights the importance of working smoke alarms.

“An operational smoke alarm will provide you with the protection and early warning that you need to give you and your family the best chance to survive and safely escape a fire in your home,” he said. “The Ontario Fire Code requires that you install a smoke alarm on every storey of your home, including basements.