At 12:53 am Monday morning, Companies 20 and 74 (Primos-Secane), RIT 37 (Upper Darby), and Medic 103-7B were dispatched to 3409 Valley Green Dr. for the house fire. Engine 20-1 (Capt. Stevenson) arrived in under a minute to find smoke showing from the 2nd floor of a 2 story row home and stretched an 1 ¾" handline. As the crew began forcing entry, a neighbor advised they believed the residents may still be trapped inside. As 20-1's crew entered the home, Chief 20-9(Hoban) assumed command while Engine 20-2 dropped an 3 ½" supply line. The crew of 20-2 entered behind 20-1 and immediately began searching on the 2nd floor. Firefighters encountered heavy smoke on the 2nd floor and fire in the front bedroom. As the fire was being knocked, the engine crews located an adult female unconscious in a rear bedroom. The female was quickly removed, in cardiac arrest, to awaiting medics. Within minutes, medics were able to regain vital signs and transport the victim in critical condition. With an unknown number of trapped occupants, units went back to work searching as Ladder 20 arrived and began throwing numerous ground ladders, performing ventilation, and securing utilities. It was soon determined all occupants were accounted for and primary and secondary searches turned up no additional victims. The fire was placed under control in about 20 minutes and was held to Company 20. Units remained on scene for several hours assisting in the police and fire marshal's investigation, as well as performing overhaul. Great job to everyone on scene. Units on Scene: Chief 20-9 had Command, Engines 20-1 and 20-2, Ladder 20, Rescue 20, Tower 74, RIT/Quint 37, Medic 103, Ambulances 103-7A and 103-7B, M-8 (Upper Darby Twp Fire Marshal), and 8th Dist. Fire Police.