Liberal firefighters responded to a residential fire alarm activation at 610 S. Lincoln Ave. this morning at 8:51 am. Police units on scene prior to the fire departments arrival reported smoke issuing from the residence. The first fire unit arrived on scene at 8:55 am. Firefighters forced entry to the residence and extinguished a fire in the living room. The fire was declared under control at 9:04 am. The residence was unoccupied at the time of the fire, which was detected and reported by a residential fire alarm system. Fire department personnel remained on scene until 9:58 am conducting investigation, smoke removal and salvage efforts. The cause of the fire was determined to be combustible materials in contact with a floor furnace and ruled accidental. The fire was contained to the area of origin; however the entire residence suffered heat and smoke damage as a result of the fire. No injuries were reported.