At approximately 1920 hours Engine 1 Ladder 3 Engine 2 Rescue 5 Utility 64 and a Wilton Engine RIT were dispatched to a reported structure fire at the Merritt Apartments on the corner of Maple and Park streets. Upon arrival units found smoke and flames showing from the 2nd floor A-side. Initially crews from Engine 1 knocked down the flames with a dry chemical extinguisher believing the fire to be electrical in nature and on the exterior of the structure. Crews from E-1 and L-3 then split up to perform a search for occupants and extension. Upon investigation the crews found one victim still asleep on the third floor and removed occupant from the building. Also crews forced entry into the 1st and 2nd floor apartments and with the use of thermal imaging cameras found fire running through the walls and ceilings on both floors. Interior units opened up and extinguished the fire. New Canaan units had the fire under control in about 20 minutes. Engine 1 remained on scene to assist FM 1 in determining the fires origin.