Maine fire officials are being assisted by electrical and heating inspectors as they continue investigating a fire that killed a father and his three children. Public Safety Department spokesman Steve McCausland says fire marshals returned Sunday to a house in Orrington that caught fire early Saturday morning in an effort to determine the cause and origin of the fire. Thirty-one-year-old Christine Johnson escaped the fire and was hospitalized for smoke inhalation. Her husband, 30-year-old Benjamin Johnson III, was killed in the blaze, along with their children, 9-year-old Ben and 4-year-old Ryan, and one girl, 8-year-old Leslie. McCausland said autopsies were expected to be completed late Sunday. Officials said the family had moved into the rented house outside of Bangor about six months ago.