Fire department officials say sprinklers inside a southeastern Idaho nursing home did not activate when a blaze erupted, destroying the building over the weekend.

The Idaho State Journal reports state and local authorities are investigating the cause of the fire that began early Saturday morning at the Safe Haven Care Center in Pocatello.

Authorities say all 49 patients were evacuated though several were treated for smoke inhalation.

Assistant fire chief Travis Smith says they are also investigating why the fire suppression system did not go off. He says it's questionable if the system was turned on, and it's possible some system parts were abandoned.

Authorities say the fire likely started in the attic of the facility and was possibly sparked by a malfunctioning light fixture.