JEANNETTE, Pa. — Jeannette Police Chief Derek Manley says investigators are treating Wednesday’s devastating fire as arson until they can safely rule it out. He said that is standard procedure for a fire of this magnitude. “The way we’re handling it is as an arson until we determine otherwise just because of the nature of what occurred, we don’t want to be lackadaisical and not cover our bases if it turns out to be one,” Manley said. “We won’t know that until we get the report from the fire marshal.” The fire Wednesday tore through one home along Guy Street, killing a dad and four of his kids. That fire also destroyed the house next door. The mother and two other children were able to escape the blaze.