National Museum of Nuclear Science & History
W. F. Boldridge worked for Clinton Laboratories at the X-10 Reactor.
Calvin B. Popwell served as a corporal in the 393rd Bombardment Squadron. He was a member of the ground crew regularly assigned to the B-29 Big Stink, and he and his crew were later reassigned to Luke the Spook.
Joseph H. Heartberg was a security guard at the University of Chicago’s Metallurgical Laboratory (“Met Lab”) during the Manhattan Project.
