At 1617 hours, York City Engines 99-1, 99-5, 99-9, and Truck 99-1 were dispatched to 409 E. Philadelphia Street for a structure fire with possible entrapment. Chief 99-2 on the scene with a working fire in a 4 story warehouse with heavy smoke showing. As companies were stretching line and preparing to go in service Deputy 99 requested the second alarm as heavy smoke was issuing from the entire building. Crews had heavy fire on the first floor rapidly extending to the floors above. With conditions deteriorating, E. Philadlephia Street command evacuated the structure at 1635 hours and performed a PAR check. A few minutes later Command requested the 3rd alarm at 1637 hours and incoming companies prepared for defensive operations. The interior floors collapsed as fire enveloped the 4 story, former Weaver Piano & Organ Co. building at the corner of E. Philadelphia and N. Broad Street that was under renovation being converted into apartments. A mayday was issued for a possible missing firefighter and the building was evacuated again at 1659 hours. The mayday was shortly cleared after an additional PAR check. Apparatus were repositioned away from the collapse zone as numerous blitz fires, ground appliances, and master streams from Trucks 99-1 (York City), 89-1 (York Area United), 1-2 (West York), 2, (West Manchester) and 11 (Nashville) flowed water on the fire for several hours that sent billowing smoke throughout the neighborhood. About 90 minutes into the incident the C/D corner of the building collapsed. The fire was contained in about 6 hours with companies remaining on the scene for over 18 hours dousing hot spots. A building on E. Philadelphia sustained some exposure damage and reports of entrapment were negative.