National Museum of Nuclear Science & History
O'Brien worked for Stone and Webster Engineering Corporation.
Arthur Watmough was an electrical engineer working for the DuPont Chamberworks Company in New Jersey from 1941 to 1947.
Harry Prosceno worked for the United States Engineer District Office.
David L. Hill was an associate experimental physicist at the University of Chicago’s Metallurgical Laboratory (“Met Lab”) during the Manhattan Project.