WWII secrets

Declassified US cables reveal lead-up to Hiroshima A-bomb decision

On Aug. 6, 1945, Maj. Gen. Leslie Groves sent a top secret cable to his superiors in Washington, D.C.

In the now declassified cable, Groves, who was in charge of the atomic bombing of Hiroshima, described what had happened.

“First there was a ball of fire, changing in a few seconds to purple clouds and flames boiling and swirling upward,” he wrote. “Entire city except outmost ends of dock areas was covered with a dark grey dust layer which joined the cloud column.”

The results, Groves told Washington, were “clearcut, successful in all respects.”

Groves’ memorandum, not publicly released until decades later, is just one of countless top-secret cables, meeting minutes, memorandums and decrypted Japanese messages sent in the days and weeks leading up to the decision by the U.S. to drop the world’s first atomic bomb on Hiroshima.