Ontario's fire marshal says that a hard-wired smoke alarm failed to function properly during a deadly fire in Etobicoke last weekend.

Frank and Maria Quintieri died Sunday after a fire started in the kitchen area of their Abigail Place home, near Martin Grove Road and Dixon Road.

The fire started the early morning hours. The cause was not immediately known.

Fire Marshal Ted Wieclawek tweeted Tuesday that the fire caused an electrical failure in a hard-wired smoke alarm within the home.

Wieclawek said homeowners should consider the added safety of using smoke alarms that are equipped with a battery back-up.