Video: 'the manhattan project trinity test'

(Saturday, July 21, 1945, 3:45 p.m. CEST; during World War II) — U.S. President Harry S. Truman received a description of the July 16, 1945, test of the atomic bomb today while at the Potsdam Conference, becoming fully aware of its awesome power for the first time (click here for a clip of this event from “American Experience: Truman” at 2:03:26).

Video: 'The World At War 1973(World War II Documentary)Episode 24-The Bomb(February–September 1945)' (July 21, 1945, at 28:02)