Delbert Johnson was a mechanical engineer with the Special Engineer Detachment (SED) at Los Alamos. Johnson worked under 1st Lieutenant Howard C. Bush and witnessed the Trinity site explosion on July 16, 1945. After the bomb test, Johnson was one of the first to enter the crater to conduct scientific measurements.
Delbert F. Johnson
Mechanical EngineerLos Alamos, NM
Leonard Krouldis was a laboratory helper at the University of Chicago’s Metallurgical Laboratory (“Met Lab”) during the Manhattan Project.