The large numbers of American casualties in the battles of Iwo Jima and Okinawa, Japan's refusal to surrender and the projected casualties during the upcoming invasion of the Japanese home islands (which some experts considered to be as high as a million dead or injured American soldiers) were some of the arguments in favor of these operations.
The first attack was carried out in 6 August 1945 on Hiroshima and second attack on Nagasaki in 9 August 1945. Resulted in over 200,000 deaths.
It remains the first and only time in the history of the human race that atomic weapons were ever used in warfare.
