The city of Nagasaki in southern Japan is marking the 75th anniversary of the US atomic bombing.
It was the second nuclear bomb dropped by the US, three days after the attack on Hiroshima.
Dwindling survivors, whose average age exceeds 83, increasingly worry about passing their lessons on to younger generations.
Here are some questions and answers about that fateful event:
– Why was Nagasaki chosen as the target?
– What happened in the attack?
– How many died?
– What about radiation?
– Who is the boy in a photo distributed by the pope?