PEORIA — The world needs more "upsiders," said Steen Metz to more than 400 people who filled the Peoria Riverfront Museum to hear his harrowing story of life in a Nazi concentration camp.

Upsiders, said the 84-year-old Metz, are people who don't just stand by and watch but people who do the right thing and act when they should. If the world had more of those, then atrocities like the Holocaust might not occur again.

The Danish native and Chicagoland resident spoke simply yet strongly about his 18 months in the Theresienstadt concentration camp, which was located in what is now the Czech Republic. No one spoke and few moved about in the large meeting room. More than a dozen people were watching the event upstairs on the museum's main floor via a Facebook Live feed as there was not enough space in the meeting room. Children sat on the floor. People stood against the wall. Metz said he was overwhelmed.

"When I got a standing ovation at the end, it was so moving. I was almost in tears," he said. "I felt bad for all those people who had to stand."

And it was for the children that Metz said he enjoyed speaking. He estimates he's spoken to thousands upon thousands of children in the past few years, hoping to educate them. He was 8 when his family was ripped from their home, put on cattle cars where they spent days en route to the camp. His mother survived the camps but his father, an attorney, died within months because of starvation and harsh working conditions.

The talk sprinkled in some humor — he would steal potatoes from the camp kitchen and joked his mother worried he would become a career thief — and then utter sadness as he described how upset he was that some Czech boys stopped playing ball with him in the camp. They had likely been deported to a death camp and killed, he told the crowd. Only 10 percent of the children — 1,500 — managed to survive their time there. Metz was one of them.

Davis Weeks, a 12-year-old who goes to Dunlap Valley Middle School, and his brother, Jacob Weeks, 10, who attends Ridgeview Elementary School, both wanted to come to hear Metz. They had never seen a Holocaust survivor speak before and said the experience was amazing.

"It was pretty remarkable the way that he was able to survive and not give up hope," Davis Weeks said after the talk.

Metz spoke as part of the annual Yom HaShoah event sponsored by the Jewish Federation of Peoria. Yom HaShoah is Hebrew for “Holocaust Remembrance Day.” Earlier in the day, readers read just some of the names of the millions of victims murdered by the Nazis. The program also served as a way to remember the shooting at a synagogue near San Diego over the weekend that left one dead and three others injured.

Sue Katz, the head of the Jewish Federation of Peoria, read to the crowd how the rabbi at that synagogue remembered the events that day. Metz, too, noted that too often, "Never again" is just words.

"We have already already talked earlier today about what happened in San Diego, what happened in Pittsburgh, what happened in the Sudan. It's genocide after genocide. We always say never again, but unfortunately we don't live by that,"

Alex Kowalczyk, a 14-year-old Normal boy, and his mother, Laura, made the drive on a rainy and windy night because they wanted to hear Metz and to learn.

"It makes you appreciate what you have and it makes you realize that you are special," Kowalczyk said, who added that he wanted to learn more.