Investigators believe they know the cause of Saturday’s housefire in the southern Iowa town of Pulaski that left three children dead. Faulty wiring in a heating system is being blamed for the fast-spreading fire that killed three siblings, 12-year-old Victoria Hilgenbrink, nine-year-old Gabriel and six-year-old Anthony. Their parents, Christopher and Robin Bollman were able to escape with three other children, while their seventh child was sleeping over at a friend’s house. One of the children who survived, seven-year-old Alex Hilgenbrink, is confined to a wheelchair and was handed out a window. He and his mother were both burned. The mother is still in the burn center at University Hospitals in Iowa City. She’s also five months pregnant.