Probably the very best "Oh Shit!" moment in history...
"Truman had been vice president for only 82 days when President Roosevelt died, April 12, 1945. He had had very little meaningful communication with Roosevelt about world affairs or domestic politics after being sworn in as vice president, and was completely uninformed about major initiatives relating to the successful prosecution of the war--notably the top secret Manhattan Project, which was about to test the world's first atomic bomb."
