As personnel where conducting multi-company drills a commercial fire alarm was dispatched to 13100 North Promenade at 10:30hrs. Prior to Engine 22 clearing the training the incident was upgraded to an industrial compactor on fire with extension to the building and the response upgraded. Arriving on scene 1st, Truck 21 reported an industrial compactor attached to the building on fire with smoke showing from the roof. As Truck 21 began fire attack, Engine 22 reverse laid for the water supply, Engine 24 came forward to assist with fire attack and Ladder 2 was assigned to check the roof for extension. With the compactor pulled away from the building, no extension found and the fire knocked down the incident was placed under control within 20-minutes. Following completion of assignments all units returned to service approximately 2-1/2-hours later.