Calls came in Sunday evening around 8:30 about a house fire in the northwest portion of the city. Firefighters arrived at 1107 Sloan St. NW to find the rear side of the single family home fully involved. Firefighters say they were able to quickly stop the fire from spreading, but damage was extensive throughout the home. Witnesses told investigators just before the fire broke out they heard an explosion in the garage. No one was home at the time. The state fire marshal is investigating.