At just before noon, the Building assignment was struck for 309 Seminole Ave in the Lester section of Tinicum Twp. Fireboard advised there was possible entrapment. The assignment brought companies 48(Tinicum), 07(Ridley Park), 08(Prospect Park), 02-5(Norwood),12(Eddystone), RIT43(Holmes), and Medic 102A to the scene. 48-9(W.Lee) arrived to heavy fire from the C/D corner on the second floor with fire impinging on the D-side exposure and PD reporting all occupants were out of the building. 48-1's crew layed in from 4th and Seminole and stretched the 1 3/4 to the second floor providing a quick knock on the fire. Engine 8 arrived shortly after and assisted establishing a secondary water supply to 48-1. After the second supply was established, the crew of five entered the B-side exposure to check for extension. No extension was found and the crew vented the dwelling via PPV fan. Crews were made available at the hour mark. Nice job to all crews on the stop!