By Jeremy Ross

CHICAGO (CBS) – Their numbers are diminishing.

The Jewish United Fund estimates about 6,000 Holocaust survivors remain in the Chicago area. One organization is using technology to better preserve their legacy.

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“They were all taken away.”

It is the chilling end of six million personal stories.

“They went into the cattle cars taken to be destroyed.”

It is also the beginning of Sam Harris’ story. One he and others can watch.

At only four years old, Harris was taken to a concentration camp in Poland. His parents and four siblings were fatally gassed. Harris is a Holocaust survivor, one of an estimated 100,000 remaining.

“At night I dream about it,” said Harris.

He and a handful of survivors are now part of a hologram program. It took about 30 hours over a series of days. Answering thousands of questions to help make Harris’ story more interactive, poignant and permanent.

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Audiences at the Illinois Holocaust Museum can ask questions to a moderator. When asked whether the Holocaust can happen again, Harris’ digital double provides an answer.

“Human beings can make it happen again,” said Harris.

Shoshana Buchhotltz-Miller is with the Illinois Holocaust Museum.

“In World War II there were too many bystanders,” she said.

Urging patrons to take a stand when faced with injustices, including equal rights and equal pay, the museum has an interactive way for patrons to get involved.

“If we do not learn from the past how can we make sure it does not happen in the future,” said Harris.

When asked if the experience to retell his story was worth it, he said it was more than that.

“It was probably the best gift I could give,” said Harris with a smile.

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His gift that helped with the hologram program began taping back in 2015. The exhibit “Take A Stand” opens to the public on Sunday.