The Demon Core: Deadliest Sphere That Killed 2 Scientists

Added: 2026-05-18

[00:00:00]At Los Alamos in 1945, scientists built the deadliest sphere on Earth. They called it the demon core. The 6-in ball of plutonium would kill two brilliant men in separate accidents just months apart. The first victim was Harry Daghlian. While working alone at night, he accidentally dropped a tungsten brick onto the core. The room filled with blue light as the plutonium went critical.

[00:00:21]Harry absorbed a lethal dose of radiation. Over 25 agonizing days, his body slowly dissolved from the inside out. Nine months later, physicist Louis Slotin was demonstrating the core to colleagues. Using only a screwdriver to keep two halves apart, he was literally tickling the dragon's tail. The screwdriver slipped. Another blue flash.

[00:00:40]Another critical reaction. Slotin threw himself over the core to shield his colleagues. He saved their lives, but doomed himself. Nine days later, he died the same horrible death as Daghlian. Two brilliant scientists, one cursed sphere of plutonium, both killed by the very weapon they helped create. The demon core had claimed its victims.