1) In August 1945, the United States dropped atomic bombs on the Japanese cities of Hiroshima on August 6th and Nagasaki on August 9th. 2) The bombs destroyed five square miles of Hiroshima and caused a blast equivalent to 12,000-15,000 tons of TNT. 3) Japan surrendered on August 15th and formally ended World War II on September 2nd after the atomic bombings caused widespread devastation and loss of life in Hiroshima and Nagasaki.