At 2050 hours, Box 2-08 toned for a residential structure fire in the area of 124 Barnett Drive in the Cove section of Penn Township. Engines 2,6, Rescue 2, Squad 20, Truck 2, and Tankers 2,6,9 made up the initial assignment. Chief 2-3 on location reporting a working fire. The working fire dispatch was requested bringing Engine 9, Rescue 37, Tanker 37, and Air 13 to the scene. Duncannon Squad 2 dropped a supply line on Barnett Drive at the end of the long driveway to set up for portable pond operations. 2 lines were stretched from Squad 2 as heavy fire issued from a 1 story (2 stories in the rear), wood frame, single family, dwelling. Companies were also advised of ammunition going off on the A/B side of the structure. Chief 2-1 arrived and assumed command. At 2128 hours, Command 2 ordered all companies out of the structure for defensive operations. 4 additional tankers were requested to the scene (Tankers 29, 17, 8, 12). Numerous hand lines and aerial stream from Truck 2 poured water on the stubborn blaze for over an hour before knocking down the bulk of the fire. Extensive overhaul was requested before companies gained control and started to release units.