On two days in August 1945, U.S. planes dropped two atomic bombs, one on Hiroshima on August 6, one on Nagasaki on August 9, the first and only time nuclear weapons have been used. Their destructive power was unprecedented, incinerating buildings and people, and leaving lifelong scars on survivors, not just physical but also psychological, and on the cities themselves. Days later, World War II was over. (AP)
Here's a look back.