I bet the Japanese were saying that right before Hiroshima.
The worlds first atomic bomb was detonated at the Trinity Site, in NM on July 16, 1945.
“Little Boy” (uranium critical mass device) was detonated about 1900 feet over on the city of Hiroshima on August 6, 1945, and on August 9, 1945 “Fat Man” (plutonium implosion device) was dropped on Nagasaki on August 9, 1945.
Few people in the world knew about these weapons before they were dropped on Japan.
The original test at the trinity site woke up people 90 miles away (night time blast). But it was explained as a accident before the bombs were dropped in Japan.