The state fire marshal has identified the cause of last week’s house fire in Keokuk which killed three firefighters and three children. State Fire Marshal Roy Marshall says one of the children turned on the right from burner on the home’s electric stove and placed something on top of the burner. Marshall says up to two hours passed from the time the burner was flipped on by the child and the fire was discovered by the mother of the house. The child who survived the fire woke the mother to alert her to the fire. Marshall says investigators will not reveal which child flipped on the stove. Marshall says while they’ve determined the cause of the fire, investigators do not yet know what killed the three firemen who tried to rescue the children. The home had two smoke detectors, but neither had a working battery.