The Omaha Fire Investigation Unit says Friday that space heaters were used throughout the home, including in the living room, where the fire began.
Investigators determined a smoke detector was in the home’s kitchen but wasn’t working because it lacked a battery.
Police say 3-year-old Gabriel Rodriguez and his 3-month-old brother Brandon Rodriguez died in the Wednesday morning fire.
The boys’ 18-year-old mother, Champaine Harn, and their sister, Adrianna Rodriguez, remained hospitalized but were expected to survive.
Witnesses said a neighbor tried to rescue the boys but couldn’t make it past the intense flames.