PHOTO GALLERY: Dark memories of Hiroshima and Nagasaki nuclear attacks

the skeleton of a Catholic Church, foreground, and an unidentified building, center, are all that remaining the blast center area after the atomic bomb of Hiroshima, Japan.

An atomic cloud billows above Hiroshima city following the explosion of the first atomic bomb to be used in warfare in Hiroshima, in this handout photo taken by the U.S. Army on August 6, 1945 (Reuters)

Local residents walk past destroyed buildings west-southwest of Aioi Bridge in Hiroshima, after the atomic bombing of the city (Reuters)

survivors of the first atomic bomb ever used in warfare are seen as they await emergency medical treatment in Hiroshima

The remains of a factory are seen, upper left, in the southern Japanese city of Nagasaki, gutted by the Aug. 9 atomic bombing.

The Roman Catholic Church of Urakami standing over the burn-razed cityscape of Nagasaki, southern Japan

the remains of a factory are seen, upper left, in the southern Japanese city of Nagasaki

Scientists and workmen rig the world's first atomic bomb to raise it up into a 100-foot tower at the Trinity bomb test site in the desert near Alamagordo, N.M. "The Bomb," which begins airing

A shortly after the first atomic bomb ever used in warfare was dropped by the United States over the Japanese city of Hiroshima, survivors are seen as they receive emergency treatment by military medics

A smoke rises around 20,000 feet above Hiroshima, Japan, after the first atomic bomb was dropped. On two days in August 1945

A mushroom cloud rises moments after the atomic bomb was dropped on Nagasaki

U.S. planes dropped two atomic bombs, one on Hiroshima, one on Nagasaki, 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 Photo, File)