At 4:15am the Box Alarm was sounded for a working Building Fire in the 900 Block of 7th Ave. Police were on location confirming a working fire in the basement with unknown occupants inside. Crews arrived and confirmed a working basement fire. Engine Company 8 quickly advanced an attack line into the basement while crews of Rescue 48 did a search for residents. Ladder 2 went to the roof via portable ladders and ventilated the roof while the rest of the crew ventilated basement windows for the Engine companies working in the basement while crews from Ladder 7 ventilated the first floor windows. Ladder 2's crew then opened up some hot spots and found no extension. Companies were made available after picking up.