Nagasaki Day 2021: How A Nuclear Weapon Destroyed A Japanese City On August 9, 1945

On August 9, 1945, three days after the bombing of Hiroshima, a US warplane hit another Japanese city. A B-29 bomber dropped a more powerful bomb on Nagasaki, a valley nestled between mountains. Together, both the bombings killed an estimated 1.2 lakh people instantly. Many more died of radiation later. It was for the first time that the world saw the devastation caused by nuclear weapons. The then Japanese emperor announced on August 15 that year the country's unconditional surrender before the Allied forces to end the mindless bloodshed and the Second World War.

Alongside Hiroshima Day on August 6, Japan marks Nagasaki Day today to raise awareness about what Japanese emperor Hirohito described as "a new and most cruel bomb". The country also tries to remind the rest of the world about the need for "peace politics" and the importance of avoiding more wars.

How was Nagasaki different from Hiroshima?

The bombing of Nagasaki was a frightening reminder of how Hiroshima was obliterated. Hiroshima, a manufacturing hub that supplied the Japanese forces, was a strategic target as it sat on the Japanese coast 500 miles from the national capital Tokyo. Nagasaki was a secondary target.

The US bomber, Bockscar, had taken off to hit the city of Kokura but had to abandon the plan because of the thick cloud cover over the island city. It then flew to Nagasaki in the mountains.

The atomic bomb "Little Boy" dropped on Hiroshima and generated a force of 12-15 kilotons of TNT. The "Fat Man", a plutonium bomb, dropped on Nagasaki and produced a 22-kiloton blast. However, the devastation was less than Hiroshima since Nagasaki was situated in a valley, which trapped the radiation from spreading far, and had a fewer population.

Why the bombings?

During World War II, Japan deployed kamikaze tactics and pilots were undertaking suicide missions to destroy US warships directly. To prevent further damage to the Allied forces, American President Harry Truman authorised the use of the most devastating weapon of war-fighting ever developed. Japan did not surrender after the Hiroshima bombing, but it did after Nagasaki. The formal agreement of its surrender was signed on September 2.

How were the bombs developed?

Fuelled by fears that Nazi Germany could overtake it in developing nuclear weapons, the US was working quietly on one of its own under a programme called the Manhattan Project. On July 16, 1945, the American scientists working on the project successfully detonated the first-ever nuclear explosion in New Mexico. Fresh from the success, the US decided to use the bombs to end the war swiftly.