Awestruck, we watched it shoot upward like a meteor coming from the earth instead of from outer space, becoming ever more alive as it climbed skyward through the white clouds. It was no longer smoke, or dust, or even a cloud of fire. It was a living thing, a new species of being born before our incredulous eyes....
--William L. Laurence
"Atomic Bomb on Nagasaki," New York Times, September 9, 1945
On August 9, 1945, just over 2 1/2 pounds of plutonium was converted to energy 1650 feet over Nagasaki.from National Archives
Two and a half pounds--about the weight of a 28 week premature newborn baby.
from National Archive