FDNY Engine! 54, Ladder! 4, and Battalion! 9 are first due on a Class III alarm

We are at the quarters for FDNY Engine 54, Ladder 4, and Battalion 9 at the corner of 48th Street and 8th Avenue, where we see a full house run for a Class III alarm on 6th Avenue between 36th and 37th Streets. All 3 companies were first due. Battalion 9 was already out on another run, so they responded from their scene. Engine 54 is a 2003 Ferrara high rise/high pressure pumper. Ladder 4 is using a spare originally used at the Fire Factory at Engine 58 and Ladder 26 up in Harlem. The ladder being used