In August 1945, a bomb dropped an atomic bomb on the Japanese city Hiroshima, there where about 80,000 people killed. The explosion was huge, the city was destroyed, and tens of thousands of people died. The bomb was 10 feet long ans weighed about 10,000 pounds. In just three days after the bomb another in Nagasaki and killed about 40,000 people. The Soviet Union declared war on Japan, and the Japanese government surrendered to the U.S and its allies. The bomb that dropped in Hiroshima was called Little Boy and the bomb that was dropped in Nagasaki was called the Fat Boy. This attack ended the war. While the Allies leaders planned the war, scientists offered another way to end the war. In the early's 1900s, scientist made the atomic bombs.