The fire whistles are becoming an all too familiar sound in parts of Elk County where some residents are already on edge.  We told you first yesterday that this house fire on Lynch Road in Saint Mary's was ruled arson.  The Crystal Fire Department got the blaze under control within minutes but it caused a lot of fire, smoke and heat damage.  Luckily, the family was not home at the time.  Neighbors say it is happening too close and too often.