According to a note on the back of this photograph, it was taken on August 6th, 1945, in the town of Kaitaichi, Japan. Kaitaichi is six miles away from Hiroshima; the photo was taken two minutes after the detonation of the first a-bomb, “Little Boy”.

This photo sat forgotten since 1953 in an archive of about 1,000 articles about the bombing, kept in Honkawa Elementary School in Hiroshima city. Most photographs of the mushroom cloud are from U.S. military sources, this alternate picture, showing the cloud broken into two parts, is quite rare.

(View on Tumblr)