FREMONT, Ind. (AP) — A mother and her three children have died following a house fire in northeastern Indiana.

The blaze in Fremont was reported about 5 a.m. Saturday and the victims were found minutes later by firefighters inside the burning home, state police said.

They were pronounced dead at hospitals. A county coroner has confirmed their identities, but their names and ages were not released Saturday. Autopsies were expected to be performed Sunday.

A preliminary investigation shows the fire appears to have started in an unoccupied area on the home’s second floor, state police said.

The cause of the fire is under investigation.