Companies received the dispatch for the garage fire to the rear of 414 Chestnut, 04-1 arrived reporting heavy fire in a large 1-1/2 story garage. 04-9 req the 2nd alarm for manpower. Companies maintained an exterior attack due to the condition of the bldg. 04-9 also reported an unk oily substance leaking from drums inside the garage, requesting spill 09 to the scene.