National Museum of Nuclear Science & History
John Ryan was a staff worker at Los Alamos during the Manhattan Project.
William J. Davis served in the 1027th Air Material Squadron.
Leo P. Hassen was a security guard at the University of Chicago’s Metallurgical Laboratory (“Met Lab”) during the Manhattan Project.
Andrew Walker was a member of the Special Engineer Detatchment (SED) at Los Alamos during the Manhattan Project.
