At 1100 hours, Company 88, Engines 54, 59-1, and 71-1, were dispatched on Box 88-3 to the 400 block of Grant Street for a possible structure fire. Chief 88 went enroute and advised of 2 calls being received. Chief 88 added Engine 71 from nearby HIA to the run and shortly before arrival requested the first alarm. Engine 55, Rescue 59, Truck 50, and Air 41 were the extra companies. Companies arrived to heavy smoke showing from a 2 story, single family, dwelling with occupant possibly still inside. 2 lines were stretched and operated via side D and knocked down a basement fire that had extended to the 1st and 2nd floors. The fire was placed under control in about 45 minutes with no injuries. Primary searches on the first and second floor were negative and it was determined the occupant was not home at the time of the fire.