The Bombing of Hiroshima and Nagasaki.

On August 6, 1945, during World War II (1939-45), an American B-29 bomber dropped the world’s first deployed atomic bomb over the Japanese city of Hiroshima.

The explosion wiped out 90 percent of the city and immediately killed 80,000 people; tens of thousands more would later die of radiation exposure.
Three days later, a second B-29 dropped another A-bomb on Nagasaki, killing an estimated 40,000 people.

At noon on August 15, 1945 (Japanese time), Emperor Hirohito announced his country's surrender in a radio broadcast. The news spread quickly, and "Victory in Japan" or "V-J Day" celebrations broke out across the United States and other Allied nations. The formal surrender agreement was signed on September 2, aboard the U.S. aircraft carrier Missouri, anchored in Tokyo Bay.

After World War II, most of Hiroshima would be rebuilt, though one destroyed section was set aside as a reminder of the effects of the atomic bomb. Each August 6, thousands of people gather at Peace Memorial Park to join in interfaith religious services commemorating the anniversary of the bombing.