The Sub-Depot Hanger (Hanger #1) was one of the original five hangers built at the air base and one of the few original PAAF buildings still standing. Large enough to house two B-29's nose to tail, it was used for modification and major repair, while the other four hangers on the field could hold only a single B-29, and it also hosted larger USO Shows. This hanger was the first set up to modify B-29's coming off the assembly line at Boeing-Wichita in the "Battle of Kansas," making it an extremely important part of the B-29 Program, and its loss would have delayed delivery of operational B-29's for the war effort overseas. On June 13, 1944, a B-29 from the 497th Bomb Group, flying a night landing mission, veered off the runway and slid against the hanger while loaded with fuel and 50 caliber ammunition. After leaving the north-south runway, it clipped the right wing of another B-29 on the parking ramp, struck a B-26 and carried it down the ramp, hit a B-17 and lost a wing, then exploded, and the fuselage, tail, and left wing slid up burning against the hanger. Four other planes suffered minor damage. Major Bernard J. Gaffney of Watertown, New York, and Lt Herman E. Grubb of Pomeroy, Pennsylvania, who lived with his wife Fay at 719 Main Street in Pratt, lost their lives in the accident. The Pratt Fire Department assisted with the fire, and without their help the hanger could not have been saved. Many Pratt-based airplanes and crewmen were lost during World War II in training accidents before seeing combat overseas; there were eleven major air crashes involving aircraft from Pratt Army Air Field on training flights, including five B-29's, four B-26's, one B-25, and one B-17, resulting in the total loss of fifty-eight Pratt airmen.