What you see when you live a century…

60 Minutes reports on the "oldest old" this week, a group of people over the age of 90, who are helping researchers understand the secrets to living a long life.

As Lesley Stahl reports, a landmark study tracks thousands of residents in a retirement community in Southern California, and the researchers behind the study say their work is beginning to reveal factors that may contribute to living longer.

The 90+'ers Stahl met also had some remarkable stories to tell:

Ruthy Stahl, 96, describes growing up during a time before refrigerators...her home used an icebox. "It was really very different," Ruthy tells Lesley Stahl.

At age 100, Jane Whistler has witnessed the advent of game-changing technology like the radio, TV and the Internet. What was it like to hear the radio for the very first time? "Wow," she tells Lesley Stahl.

One of the greatest events Lou Tirado, a World War II veteran and a 90+ study participant, witnessed was the first time man set foot on the moon. "They used to say it was made out of cheese," Lou tells Lesley Stahl.

You'd never be able to tell from 96-year-old Ruthy Stahl's active lifestyle and sharp mind that she was exposed to radiation and once glowed green during WWII. She tells Lesley Stahl about the dangerous job she used to do.

During World War II, Lou Tirado served as a B-17 gunner. When his plane was shot down over Germany, he became a prisoner of war. Tirado tells Lesley Stahl how he was freed not by the U.S., but by the Russians.

96-year-old Ted Rosenbaum describes testifying at the McCarthy hearings. He was targeted because of his involvement in an organization that aided the poor. "It so angered me, I wanted to put [McCarthy] in his spot," Ted tells Lesley Stahl.

If American tycoon Howard Hughes asked you to move to Europe with two hours' notice, would you? Find out what Henry Tornell decided to do when Hughes asked him to drop everything.

Helen Weil escaped Nazi Germany as a teenager -- forced to leave her parents and younger sister behind. Now 93, Weil recounts the infamous Kristallnacht, when her house was attacked in the middle of the night.

Editor's Note: This segment was originally published May 4, 2014