On Aug. 6, 1945, the U.S. bomber Enola Gay dropped the first-ever atomic bomb on Hiroshima, instantly killing tens of thousands of people. Three days later, the U.S. dropped a second bomb on Nagasaki.

The two aerial bombings — the only instances of nuclear weapons being used in an armed conflict — led to between 150,000 and 246,000 deaths by the end of the year, while survivors suffered after effects for years to come.

But since those four days of nuclear devastation, little attention has been paid to one group of survivors — North Koreans.

Under Japanese colonial rule,