Norwalk engines 4, 1, Truck 1, Rescue 2, Car 2 and Truck 2 (RIT)  were called to Mola Rd. on tuesday afternoon, March 6, for reported smoke in the basement.  Firefighters were met with a smoke condition inside the residence and quickly had a 1 3/4 preconnect stretched to the interior.  After making their way to the basement, firefighters came upon what appeared to be a furnace explosion with extension to surrounding combustibles.  The attack line was used to extinguish the surrounding fire as the fire was contained to the area of origin.  Although the fire was contained to the area of origin, there was smoke damage to the upper floors.  The fire is under investigation.