20,000 ton bomb was 2,000 times more powerful than any bomb ever used before.
was one of the main supply depots for the Japanese army.
bomb was dropped from the Enola Gay (an American B-29 Superfortress) at 0815 local
The bomb was dropped 10 days after the Japanese refused to sign an unconditional
surrender, the 'Potsdam declaration'.
Harry S Truman announced:
they do not now accept our terms they may expect a rain of ruin from the air the
like of which has never been seen on Earth. Behind this air attack will follow
by sea and land forces in such number and power as they have not yet seen, but
with fighting skill of which they are already aware."