At 11:20 am Friday, the Knoxville Fire Department was dispatched to the 800 blk of W Rock Island for a reported structure fire. When crews arrived, they found black smoke coming from the front door of the residence. Crews made entry and found smoke throughout the residence. Crews made their way into the basement to find the furnace on fire. The fire was quickly extinguished, but not before it caused smoke damage throughout the home. The department was able to use vent fans to remove the lingering smoke from the home. The occupant was able to escape safely, due to operational smoke alarms in the home. The Knoxville Fire Department was assisted on scene by Knoxville Police Department, Marion County EMA, Alliant Energy, and Knoxville Water Department.