Louis Slotin

Louis Alexander Slotin was a brilliant Canadian physical chemist from Winnipeg who earned degrees at the University of Manitoba and King's College London before joining the Manhattan Project at Los Alamos. Slotin served as the laboratory's chief armorer, assembling the plutonium core for the Trinity test and postwar atomic weapon components.

On May 21, 1946, while conducting a criticality experiment on the plutonium core known as the "demon core," his screwdriver slipped, causing a prompt supercritical reaction. Slotin instantly knocked away the beryllium hemisphere and shielded seven other scientists with his body, absorbing a lethal dose of gamma and neutron radiation to save his colleagues, dying nine days later.