Operation Downfall - Hiroshima and Nagasaki - A/H

The following information

Operation Downfall

Operation Downfall was the plan to invade the Japanese Home Islands. 

Japan is circled in red.  Korea and China are to the left.

Okinawa showed just how costly it would be.  

The planners of the attack learned that the Japanese Army was giving lunge mine weapons (someone using this weapon would shove the sticks on the end of it to cause the explosion.), and other weapons, to civilians, even young girls, so they could attack the invading Americans.  They also had plans to strap bombs onto people who would go blow up U.S. ships, tanks, and soldiers themselves.

Lunge Mine: The 3 sticks were triggers that would cause the explosion when pressed against something

We would wind up having to fight ALL Japanese. One Japanese citizen called to prepare for battle was high school girl, Yukiko Kasai. The army gave her a hand spike to use as a weapon.

Hand spike to use as a weapon

They told her, "Even killing one American soldier will do. … You must aim for the stomach.’

The invading forces would be facing at least 900,00 Japanese soldiers and all the civilians who were prepared to fight. The estimates of casualties (killed and wounded) were as follows:

• 1,700,000 to 4,000,000 American killed and wounded
  800,000 of those would be killed
• 5,000,000 to 10,000,000 Japanese killed

But...We had something else that made this kind of attack not necesary.

Hiroshima and Nagasaki – Dropping The Atomic Bombs
August 6th and 9th, 1945

Development of The Atomic Bomb

What many did not know was there was another weapon being developed. In October of 1939 Two scientists, Leó Szilárd and Albert Einstein, sent a letter to President Roosevelt. They told the President that it was likely that in the near future it would become possible to use science to cause an explosion that would make and release  HUGE amounts of power. They made the point that this technology could be used to produce weapons more powerful than anyone imagined.

It was known that Germany was experimenting and trying to develop this technology.  So the decision was made to start a program to discover what could be done. It would eventually employ 130,000 people in at least 3 different countries, and cost $2,000,000,000.

In order to really develop this idea they needed space, lots of it.   They needed to have rooms to do experiments in, and other rooms for scientists and workers to live in. One way this was done in the area of Los Alamos, New Mexico.

You can see Los Alamos in the northern part of this map.

The scientists in charge of the plan came to the area, and eventually were shown a school named the Los Alamos Ranch School. It was a school where boys went, and stayed there while learning. It was a boarding school.

You can see all the buildings that would be useful to the U.S. Government in building the A-Bomb.

They sent a letter to the school telling them the government was taking their school:

Mr. A. J. Connell President and Director Los Alamos Ranch School Espanola, New Mexico Dear Sir: You are advised that it has been determined necessary to the interests of the United States in the prosecution of the War that the property of the Los Alamos Ranch School be acquired for military purposes. Therefore, pursuant to existing law, a condemnation proceeding will be instituted in the United States District Court for the District of New Mexico to acquire all of the school's lands and buildings, together with all personal property owned by the school and used in connection with its operation. Although the acquisition of this property is of the utmost importance in the prosecution of the war, it has been determined that it will not be necessary for you to surrender complete possession of the premises until February 8, 1943. It is felt that this procedure will enable you to complete the first term of the regular school year without interruption. You are further advised that all records pertaining to the aforesaid condemnation proceeding will be sealed, by order of the Court, and public inspection of such records will be prohibited. Accordingly, it is requested that you refrain from making the reasons for the closing of the school known to the public at large. Sincerely Yours, [Henry Stimson] Secretary of War.

This is the actual letter that was received. Does it look fancy enough for something that really was such a big deal?

Once the bomb was developed they needed to test it. Even the scientists had no idea of what would really happen. The testing required different steps:

Setting up the test. Look at how big the bomb piece was at the end

Moving the plutonium core (the part that makes the explosion). It starts a chain reaction that releases a LOT of energy. That can destroy things.
Were they really doing this safely???

The “Jumbo Device” that was designed as a backup to hold the main explosive thing in case the nuclear part did not explode. It cost $12 million to build, and was a steel cylinder 10 feet in diameter and 25 feet long. Its walls were 14 inches thick and the entire device weighed 200 tons.

This was the Trinity Explosion (The very first nuclear explosion) in color

This is the main scientist, Robert J. Oppenheimer, speaking about the 1st nuclear blast. Look at his facial expressions, and the way he was talking. What does that indicate about what he was thinking?

It was another version of this weapon that President Truman (Roosevelt had died in April, 1945) decided to drop on Japan in August when they would not surrender.

First Bomb -  Dropped on Hiroshima on August 6th, 1945.

On 6 August 1945, a specially changed  B-29 bomber lifted off from an airfield on an island in the Pacific named Tinian.   The bomb was dropped from the plane at  31,600 feet.

Enola Gay - The B-29 that dropped The Bomb

The bomb exploded  1,750 feet  in the air. The blast was later estimated to be the equal of 13,000  tons of TNT (an explosive)  An area approximately 4.7 square miles (a square that has each side equal to 4.7 miles) was completely destroyed. Japanese officials determined that 69% of Hiroshima's buildings were destroyed and another 6–7% damaged. About 70,000 to 80,000 people, or some 30% of the population of Hiroshima, were killed immediately, and another 70,000 injured.

The middle of the place in Hiroshima that was destroyed by the bomb.

This video shows the explosion over Hiroshima

See a movie clip of what it might have been like:

Second Bomb – Dropped on Nagasaki  on August 9th, 1945

The Japanese did not surrender, even after they witnessed the power of the new weapon we had.  President Truman then decided to drop another atomic bomb. It wound up being released over the city of Nagasaki because the weather over the first target city made hard it to see.

Eplosion of the bomb over Nagasaki

Japan surrendered on August 15th, 1945 when Emperor Hirohito made a radio broadcast. It was called VJ Day, which meant Victory over Japan.

The Japanese delegation aboard the USS Missouri, a battleship

The war was over.

Hideki Tojo, the former military leader of Japan, tried to kill himself, but was captured, tried as a war criminal, and then executed on December 23rd, 1948.