Company 3 was dispatched along with other south county units to the 3700 block of Colonial Avenue at around 8:15pm for a reported structure fire. While enroute Wagon 3 requested a working fire dispatch due to heavy smoke seen coming from the area.  Wagon 3 arrived to find a 2 story commercial structure with heavy fire showing from the Bravo side.  Wagon 3's crew stretched a 1 3/4 inch attack line and made a quick knock down from the exterior. Engine 3 and Ladder 3 arrived minutes after the Wagon, secured the Wagon's water supply, and the ladder crew secured means of egress from the house.  The Wagon crew made an aggressive interior attack, confining the fire to the fire room with minor extension to the second floor. Engine 3's crew performed a quick primary search of the first and second floor and ventilated.  Within fifteen minutes command made a can handle for units onscene.  Crews from stations 3, 7, and 11 were onscene for a little under two hours before returning to service.