Investigators say a house fire that killed two young boys in central Washington state is suspicious.

Battalion Chief Mike Price told KPQ-AM suspicions were raised because the fire in Wenatchee spread so quickly.

The house, divided into upstairs and downstairs apartments, was fully involved in flames when firefighters arrived Thursday night. Firefighters found the bodies of the boys, ages 4 and 6, on the ground floor. Upstairs residents got out safely.

The boys' mother, Lucia Garcia, told The Wenatchee World she was away from home with her mother at the time. She says the boys' father, Israel Alejandre, was burned trying to save them. He was airlifted to Harborview Medical Center in Seattle in critical condition.