National Museum of Nuclear Science & History
Barrett worked for Stone and Webster Engineering Corporation.
John P. McBride was a research assistant in the Chemistry Division at the Chicago Met Lab. He was later assigned to Oak Ridge, where he worked on plutonium purification and on isolating uranium-233 isotopes from thorium.
Ben Benjamin was a sergeant in the Special Engineer Detachment during the Manhattan Project. He had previously worked in industry making lenses and prisms, and was assigned to the Optics Group to help with photographing the Trinity Test.
