National Museum of Nuclear Science & History
Barr worked for Stone and Webster Engineering Corporation.
Julian Mack was an American physicist. Mack was the leader of Group G-11 (Optics), the photography group, in the Weapons Physics Division at Los Alamos during the Manhattan Project.
George W. Marquardt served as a captain in the 393rd Bombardment Squadron. Although he was regularly assigned to the Up An’ Atom, he flew in the mission to bomb Hiroshima as the aircraft commander of the Necessary Evil.
