Shortly before 1400hrs Station 46 activated to assist in the Borough of Donora which had 3 structures on fire. Engine 46 arrived in the Borough and was assigned to stretch an additional 5 inch supply line to Truck 63(Carroll Twp.) and pump the hydrant. Engine 46 operator handled, while crew was assigned to help with exposure control and proceeded to assist with overhaul. Crew remained on scene approximately four and a half hours before returning in service. New Eagle was added to all first due alarms while working in the "D."