Irvin Leifer was the son of Sophie Gumerman Leifer. He served in the 52nd Bomber Squadron, 29th Bomber Group, Very Heavy, as a Sergeant and Radar Observer Mechanic of B-29 Superfortress #42-63571 during World War II.

On the early morning of May 11, 1945, a Boeing B-29 Superfortress #42-63571, commanded by 2nd Lt. Clemence W. Halteman Jr., departed Guam on a Twentieth Air Force mission targeting the Kobe Industrial Area in Japan. Shortly after takeoff, the aircraft was involved in a catastrophic accident and crashed before reaching its destination. All eleven crew members were lost. Wartime records initially reported one crew member as killed and ten as missing; however, the missing airmen were subsequently presumed dead, and no survivors were ever found. While contemporary accounts reported that the precise cause of the accident was never publicly disclosed, surviving records do not provide a definitive explanation.

Sgt Leifer was reported missing in Action, and his name is memorialized in the Tablets of the Missing in the Honolulu Memorial, Honolulu, Honolulu County, Hawaii, USA.

Source of information: www.findagrave.com, aviation-safety.net, weremember.abmc.gov