ONALASKA, Wis. -

Onalaska firefighters are investigating what caused a house fire at 935 4th Avenue North on Tuesday morning.

Onalaska Fire Chief Don Dominick says no one was injured in the fire and the family was not home at the time.

Chief Dominick says when firefighters arrived on scene around 6:14 a.m., the fire had already spread from the first floor into the attic. It took firefighters about 30 minutes to put out the fire. Neighboring homes were not damaged.

The family displaced by the fire is staying with relatives, Chief Dominick said.

"This is a time that we ask people, as we do year round, to have a working smoke detector and make sure you’re checking monthly that the batteries work," Chief Dominick said.