For the last 40 years of his life, Henry Oertelt dedicated his life to teaching school and community groups in the Midwest about his experiences in the Holocaust because he wanted to ensure the tragedy was never forgotten.

Oertelt, 90, died five years ago in his adopted hometown of St. Paul, Minn., but his granddaughter, Corey Samuels, has spent the past eight years ensuring that his legacy and memories live on. The Cardiff resident co-produced a short film about Oertelt and last week she flew to Washington, D.C., to donate his personal Holocaust-related artifacts to the U.S. Holocaust Memorial Museum.

Samuels, a 47-year-old software business analyst, said that from a very young age she can remember going to hear her grandfather tell his harrowing story in high schools around Minnesota.

“My family would go and see him speak to classrooms and I was always struck by how he could keep a roomful of kids riveted for a couple of hours at a time,” Samuels said. “He was so gifted at engaging people and I was proud that his message was always about tolerance against hate.”

Arthur Karl Heinz Oertelt was born to Jewish parents in Berlin, Germany, in 1921. His father died when he was young and his seamstress mother struggled to support the young “Heinz” and his older brother Kurt. After Hitler rose to power in 1933, the Oertelts’ rights and possessions were gradually stripped away until they were sent to the Theresienstadt labor camp in 1943.

From there, the family was split up and transferred to several different prison camps until the end of the war. The brothers would survive but their mother died in the Auschwitz death camp. Oertelt was liberated by U.S. troops in April 1945 during the infamous Flossenbürg death march.

Fearing attack, the Flossenbürg concentration camp guards evacuated on foot the camp’s 22,000 prisoners, including 1,700 Jews. During their forced march toward the Dachau death camp, 7,000 inmates collapsed and died or were shot because they couldn’t keep up.

Later in life, Oertelt would tell school groups that he owed his survival during World War II to a chain of 18 coincidences, chance encounters, kindnesses by others and good fortune. He was a healthy and wily young teenager when they arrived at the Theresienstadt ghetto and he quickly figured out how to skirt the rules to achieve better living conditions and food for his family to survive. He’d also apprenticed as a furniture maker before the war, so the Nazis saw value in his skills and kept him alive. Then after the war, many people helped him find work, news of his extended family (who all died in the camps) and passage to the U.S.

Rather than be bitter, Oertelt felt his survival was a gift from God. In 2000, he published his autobiography, “An Unbroken Chain: My Journey through the Nazi Holocaust.” In it he details the 18 links in the chain that kept him alive. In Hebrew, 18 is the numerical value for the Hebrew word “chai,” which means “life.”

After the war, Oertelt returned to Berlin, married Inge Fromm and they immigrated to St. Paul. For 10 years after the war, he never spoke of his war experiences until a chance encounter with a former U.S. soldier who had been among his liberators near Flossenbürg. He and others encouraged Oertelt — who Americanized his first name of Heinz to “Henry” — to share his story with the public.

Oertelt continued to travel and talk about his experiences until his late 80s. His daughter, Stephanie Oertelt-Samuels, was his driver, his aide and she co-wrote his autobiography. When she was diagnosed with brain cancer, she asked her daughter, Corey Samuels, to take her place as the family driver and historian.

“In the last years, I was increasingly aware that the torch would be handed to me as my grandfather got older and my mom got sick and it affected her speech. I saw this as a very important responsibility,” Samuels said.

Eight years ago, Samuels was on a business trip in the Virgin Islands when she met Florida film producer Stephanie Silverman Houser. After hearing Oertelt’s remarkable story and later getting his blessing, Houser became determined to turn it into a feature film and Samuels signed on as associate producer.

They were still in the fundraising stages of the film project in 2010 when Samuels’ mother died; her grandfather followed a year later. The women decided rather than push for years to make a full-length film, they would use what money they’d raised to produce “Becoming Henry,” a nine-minute short film set at the moment in 1955 when Oertelt made the decision to begin sharing his story. The 2013 film played the festival circuit for two years and was then released free online for educational purposes.

Two years ago, Samuels moved to Cardiff but she remained in close touch with Houser, who became active in the Holocaust Museum’s advisory committee chapter in Boca Raton, Fla. When Houser learned the museum was building the Shapell Center, a new wing designed to store the artifacts of Holocaust survivors, she thought it would be the ideal repository for Oertelt’s memorabilia.

Oertelt visited the museum when it opened in 1993 and his “survivor” biography is one of those printed on the cards handed to museum visitors to personalize their experience.

On June 27, Samuels and Houser met in Washington and worked with a museum curator to go through the collection, which included family and historical photographs, travel documents, a video recording of Oertelt speaking to an audience at St. Cloud State University and scripts he used in his presentations.

“What was really amazing was that it was such a personal experience,” Samuels said. “The curators are so sensitive to the families who may or may not be ready to do this. She spent so much time with us and we really felt it was the right place for these things to be saved.”

Even with her grandfather gone and the film project finished, Samuels said she expects his story to continue being a part of her life.

“I don’t think it will ever go away,” she said. “The film just keeps paying dividends and Stephanie and I still get approached regularly to answer questions and talk about the film and my grandfather’s story. I want to continue to do it as long as I can.”