Until not so long ago, renowned actor Mikijiro Hira had not talked much in public about his late mother, Hisayo, who barely survived the atomic bombing of Hiroshima.

The bombing, which took place on Aug. 6, 1945, is estimated to have ultimately killed, by the end of that year, about 140,000 people.

Hisayo, who was in her 30s, was walking to work at a post office. As she bent down beside a building to tie a shoelace, there was a strong flash of light.