We turned the switch, saw the flashes, watched for ten minutes, then switched everything off and went home. That night I knew the world was headed for sorrow.
Source: On 1939 experiment that confirmed atoms could be split; recalled on his death, 30 May 1964.
-- Leo Szilard, (Feb 11 1898-1964), Hungarian-US scientist; He, with Enrico Fermi, conducted the first nuclear chain reaction, 1942; was instrumental in initiating the Manhattan Project to build the atom bomb.