At 0755 hours, Box 37-1 sent companies to 3417 N. 6th Street for a chimney fire. Reports indicated the house was filling up with smoke. PD on location reporting a working basement fire. Truck 32 (Progress) arrived on location with a good smoke condition from the third floor. Engine 37-1 (Rescue) arrived and laid a line from the north. Companies made an aggressive attack on an occupied, 2.5 story, wood frame, single family dwelling. Crews had difficulty locating the fire initially but once the walls were opened up the fire was quickly knocked down. Companies remianed on the scene performing overhaul before returning to quarters.