National Museum of Nuclear Science & History
Harold Hoover was a member of the Special Engineer Detachment during the Manhattan Project. He worked as a filter foreman at the Y-12 Plant, but his real job was in counterintelligence, to ensure no sabotage occurred.
Langworthy worked in the 100 D Area at Hanford during the Manhattan Project.
Henry Fritz was a chemist in the Special Engineering Detachment assigned to the K-25 Plant in Oak Ridge, Tennesee.