In what was to be the final act of World War II in the Pacific, the United States made the first and only use of nuclear power as a weapon in the bombing of Hiroshima and Nagasaki on August 6th and 9th (US dates), 1945.
George Weller of the Chicago Daily News snuck in to Nagasaki in early September 1945 and became the first American journalist to see the destruction. His stories were censored, and official sources maintained control of news about the bombings and the aftermath for many years.
Mainichi Daily News has a pair of photo galleries of Hiroshima bomb damage and how the city remembers the bomb today.