Children look at candles and messages placed around the A-bomb Dome, dedicated to atomic bomb victims, near ground zero, Hiroshima.
In August 1945, U.S. planes dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki, effectively ending World War II. Few who witnessed the attacks remain, yet the destruction is etched in human memory. A buildup of ever-more-powerful nuclear weapons followed Fat Man and Little Boy; none have been used in war. The 60th anniversary of the bombings prompts more reflections on one of history's most dramatic lessons.