E35 was dispatched to a dumpster fire. Enroute Metcom upgraded to an outbuilding fire. ACSO was on scene and reported a row of garages on fire. M35, E42, TW45, BC32 were added to the upgraded outbuilding fire. On scene E35 reported a working fire in a dumpster, took command, and began fire attack. Safety 34 arrived on scene and assumed command. Crews worked for a few with fire attack and search. Minor extension to the exterior of the garages.