PORTSMOUTH, Ohio (AP) — A fire roared through a two-story house early Friday, killing a woman and her three children, while a passerby helped rescue others from the flames, officials said.

Investigators think the fire started in the rear of the house, but no cause was immediately determined.

Killed in the fire were Lisa Rose and her children, 3-year-old Aleia Lynn Rose; 2-year-old Annabelle Rose; and 11-month-old Allison Rose, the fire chief said.

The home was not equipped with smoke detectors, said Shane Cartmill, a spokesman for the State Fire Marshal's Office.