Just before 2 a.m. this morning , Acting Chief 9A, Engine 94, Truck 9 and the Ambulance were alerted to respond to the 6100 block of Baltimore avenue for reports of a house on fire. Supplemented calls advised a corrected address for the 6700 hundred block. Battalion Chief 4 arrived on scene with heavy fire showing from the second floor as well as fire through the roof. Upon completion of a 360, it was confirmed that there was fire in the basement as well as on the first floor. Engine Company 9 took the first arriving engine responsibilities and quickly stretched a line around the rear to the side Charlie access. The engine company began to extinguish the fire in the basement while the truck company who was the second due truck began to perform a search of the house. Shortly after, evacuation tones were sounded and everyone operating was removed from the house. On the bravo side of the house, there was a partial collapse and units were reported to be trapped underneath the debris. Members helped the units self extricate and the mayday that was called was quickly mitigated. As conditions improved Engine 94 was then directed to the second floor to complete extinguishing the fire and Ambulance 809 was directed to takeover rehab for the duration of the incident. Company 9 operated for approximately 2.5 hours before returning to service.