The images are iconic... a mushroom cloud erupts over the city of Nagasaki in 1945, in the world's second wartime atomic bombing ever.
Some 150,000 people died in the attack and from the subsequent radiation sickness.
69 years later, Japan remembers the victims during a memorial service.
Visitors observed a moment of silence at 11:02 in the morning, the exact time the bomb was dropped.
After their surrender to Allied forces, Japan adopted a pacifist constitution.
Recently though Prime Minister Shinzo Abe lifted the country's ban on aiding other countries under attack- the most significant change to country's security policies in decades.