MUNDELEIN, Ill. (CBS) -- Hearing about the Holocaust from someone who saw it with his own eyes is a lesson that some students in the far north suburbs won't soon forget.
CBS 2's Marissa Parra on Wednesday visited Carmel Catholic High School in Mundelein, where a witness to one of history's greatest atrocities illuminated the lessons of the Holocaust.
The Carmel students are taking a class titled "Holocaust and World Genocide."
"It's just hard to kind of realize that humans have that capability," said Carmel student Leah Ulbrich.
But for George Levy Mueller, 89, the Holocaust was his very childhood.
He described a situation where there was no food and "people were looking like skeletons." He described a memory in which he was so hungry that he ended up gnawing on a piece of wood.
"People would drop dead from hunger," Mueller said. "My legs were getting thinner – there was like an indentation."
The memories are painful and graphic.
"They used bulldozers to put all those dead people; prisoners into bodies into these graves," Mueller said.
And then there was the most painful memory of all. Mueller recalls waving goodbye to his mother from a Kindertransport train – watching her grow smaller in the distance. He never saw her again.
Mueller was born in Germany. On Nov. 9, 1938 during Kristallnacht – the horrific night when the Nazis set synagogues on fire and damaged Jewish homes, schools, and businesses – Mueller was rounded up along with his father, uncle, and other Jewish men and hauled to a Nazi camp.
After Kristallnacht, Mueller and his sister, Ursula, were sent from Germany to Holland, where they were hidden in a convent for years. But they ended up being deported and sent to concentration camps.
Mueller was one of 1,300 children in his first camp.
"When they got there, all the kids were gassed – and there were only five kids left," Mueller said. "I was one of the five."
His sister, Ursula, also survived. From the Vught and Westerbork concentration camps, they were ultimately moved to Bergen-Belsen – where more than 100,000 Jews were killed between 1941 and 1945.
At the time, Mueller was just barely shy of his teenage years.
Mueller and his sister were liberated by the Russian Army while on a death train in 1945. They came to the United States in 1947.
Even then, Mueller lived in fear for a while. For example, Mueller is not his given last name – he replaced the name "Levy" with "Mueller" so he would blend in.
"I didn't want people to know I was Jewish," he said.
But it was Holocaust deniers who really fueled his anger and desire to take action.
"I have met people who tell me the Holocaust really didn't happen," Mueller said.
Thus, it became a sense of duty.
And now, while he can, Mueller gives the same talk to a different sea of faces several times a month.
"I'm still standing here," he said.
He stands a survivor, and a proud grandfather to 15 – with a lesson in forgiveness.
"I can't go around life hating people," he said. "I'll leave that up to god and I'll just go along with it."
Carmel students were left with strong impressions.
"It's one thing to hear about it, it's another to hear from someone who actually lived through it," Ulbrich said.
"People who were the Nazis were also students at one point, and if they'd learned how to have humanity and respect others, then maybe it wouldn't have happened," said Carmel student Alexandra Monroe.
Mueller is also the author of "Lucie's Hope," a book about his mother's sacrifice and about his own journey.
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