​On remembering Hiroshima, 70 years later

Seventy years ago today America dropped a plutonium bomb on the Japanese city of Nagasaki. Just three days earlier, the U.S. dropped a uranium bomb on Hiroshima. The two nuclear attacks were designed to bring World War II to a swift end without many more American casualties. Our Seth Doane traveled to Hiroshima to take a look back for us:

In Nagasaki today, a solemn ceremony marked the 70th anniversary of the bombing -- while on Thursday, paper lanterns carrying messages of peace were floated in front of the iconic "Hiroshima dome," which stands as a reminder of the power of America's bomb.

Keiko Ogura was just eight years old when the bomb was dropped a mile-and-a-half from her home. She told Doane even today, she cannot forget that day.

Most of Japan's major cities had already been bombed, and many in Hiroshima had a feeling they were going to be next.

"My father said something will happen soon," Ogura recalled. "And that morning he said, 'Today it will happen. You stay home.' Then I didn't go to school. Because of that, I was near my house."

"You think that saved your life?" Doane asked.

"Yes, of course."

On a nondescript side street a plaque marks the spot where, directly overhead, the atomic bomb was exploded. Nearly everyone in this area died in an instant.

At the Hiroshima Peace Memorial Museum, a model shows the giant fireball that engulfed the city.

The heat from the explosion reached as high as 7,000 degrees. Up to 80,000 people were killed instantly.

Everyday items were incinerated: a school lunch box, and a tricycle a child had been riding just feet from Ground Zero.

"We want people to understand how inhumane nuclear weapons are," said Kenji Shiga, the museum's director.

Keiko Ogura remembers survivors looking like "ghosts."

"We shouldn't repeat the evil," she said. "This is the reason why we continuously tell our story.

She told Doane this inscription on a memorial in the center of the city - "Rest in peace for we shall not repeat the evil" -- is a reminder for her: tell her story, with the hope this chapter of history will never be repeated.

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