The leaders of nearly 50 countries are going to Israel to participate in a special forum on Thursday to mark the 75th anniversary of the liberation of the Auschwitz-Birkenau concentration camp in World War II.

The event commemorates the 6 million Jews whom the Nazis and their collaborators killed during World War II. According to the publication Israel Hayom, a study by the Holocaust Survivors’ Rights Authority found that 192,000 Holocaust survivors live in Israel and nearly 40 percent are older than 85.

Yet a 2018 survey in the United States found that two-thirds of millennials could not identify Auschwitz — where more than 1 million Jews were murdered during the war — and 22 percent said they had never heard of the Holocaust or aren’t sure exactly what they know about it.

The United Nations set Jan. 27 as International Holocaust Remembrance Day and urged countries to honor the victims. There will be events in the United States, including one on Friday by the United States Holocaust Memorial Museum.

This post is written by an award-winning author and focuses on how she tries to teach young people about the Holocaust. She is Margaret McMullan, author of nine books, including the novel “In My Mother’s House” and the anthology “Every Father’s Daughter.” Her new book, “Where the Angels Lived: One Family’s Story of Exile, Loss, and Return,” is about the Holocaust, and she received a Fulbright scholarship to conduct research in Hungary. You can follow her on Twitter: @MargaretMcMulla.

By Margaret McMullan

At Hebron Elementary in Evansville, Ind., I showed a picture of Nazi leader Adolf Hitler standing in an open car one day more than 80 years ago in Vienna. My mother saw him that day, when she was at the dentist’s office having a cavity filled. There was a parade, and my mother, who was 9 years old, went to the window and clapped alongside everyone else. It was March 12, 1938. The students outside in the streets cheering Hitler with swastika flags were the same age as the fifth-graders in front of me in this Evansville classroom.

When Cypress, a committee that trains teachers how to teach the Holocaust, invited me to talk to middle schools, I began to worry: Were fifth-graders too young for the material?

Their teacher assured me that they are not too young. They have already read Anne Frank’s “The Diary of a Young Girl” and Lois Lowry’s “Number the Stars.” Last year, Eva Kor, who survived medical experiments overseen by Nazi doctor Josef Mengele, visited them.

I can’t pull up my sleeve and show them numbers that the Nazis tattooed on my arm, but I can tell these students the real-life stories my mother and other witnesses told me, as well as other stories I have uncovered in my research.

In 2010, I received a Fulbright scholarship to teach at the University of Pécs in Hungary, where I also researched my mother’s Jewish family for my memoir, “Where the Angels Lived: One Family’s Story of Exile, Loss, and Return.” Most of the members of that family were murdered in the Holocaust.

Researching was challenging. In Pécs, there is no evidence, no markers of the deportation of more than 4,000 Hungarian Jews in 1944 to Auschwitz and other concentration camps. At the city museum in Budapest, I asked the director where the internment camp was, which held captured Jews before they were loaded into cattle cars and deported. She said that no such camp existed. Later, however, I found documents at Yad Vashem — the Holocaust museum in Jerusalem — that proved the camps had been across the street from the train station in Pécs.

When I returned to the United States, I was determined to do my part to make those hashtags come true: #NeverForget. #AlwaysRemember.

At Hebron Elementary and elsewhere, I walk students through my search about my mother’s uncle, Richárd. I show a picture of his house in Pécs, where Nazis arrested him, then seized his home and everything else he owned. They held him at the deportation center before they loaded him on a cattle car headed for the concentration camp. I show them the documents from Yad Vashem and the Mauthausen Memorial in Austria.

Reason for deportation: Ung. Jude. Ung is short for Hungarian. Jude is Jew.

One boy raised his hand and said: “But he got his home back, right?”

“Richárd never returned to Pécs,” I said. “He was murdered.”

The boy and the rest of the class went quiet.

I showed a picture of Richárd and his death registry, dated April 30, 1944, with a black line drawn through his name.

“That’s just not right,” the boy said quietly.

Six million Jews and millions of others were murdered by the Nazis, numbers so enormous that they are overwhelming. I find that it is the stories of individuals that take hold in the minds of children.

How young is too young to introduce students to historical evil? I don’t know, but I do know that talking with students about the Holocaust is essential. Anti-Semitic crimes, on the rise globally, doubled in the United States last year, according to the Anti-Defamation League.

Since last May, I have visited students in grades five through 12 in Indiana, Illinois, Ohio, New York, Virginia, Louisiana, Florida, Mississippi, Maine, Massachusetts — and even in Israel.

At the Walworth Barbour American International School outside Tel Aviv, a fifth-grade girl asked how I knew that the information about Richárd and the concentration camp was accurate. “Maybe someone just made it up,” she said. “Maybe it’s fake.”

Clearly, she is suspicious of everything. I appreciate her questioning, but I can’t help but wonder if she’s questioning the Holocaust, too. I never thought that writing a book about the importance of remembering history and the Holocaust would be controversial or questioned. I never thought that remembering would involve defending.

I told her that these documents are not “fake news.” I explained that we have these lists because three prisoners at the Mauthausen-Gusen concentration camp (a vast complex in Austria and part of Germany) buried this material, even though German SS told them to burn the evidence in 1945. If it weren’t for those men, I wouldn’t know what I know about Richárd, a man whom, like so many others, the Nazis wanted forgotten.

At Pike High School in Indianapolis, one girl wanted to know why my family didn’t just leave Hungary before the Holocaust.

I explained that changes in Pécs happened slowly. First there were laws requiring Jews to wear yellow stars. Then came other laws forcing Jews to shut down their businesses, to turn in their radios, bicycles, musical instruments, art. The definition of who was Jewish kept changing, too. Each time a new law was announced, many thought: “Just wait. This craziness will all blow over.” Some who wanted to leave couldn’t.

My grandfather didn’t take Hitler seriously. He spoke with his colleagues at the University of Vienna about this ridiculous tyrant, a fool with bad hair, a loudmouth who couldn’t even get into art school.

At Bloomington High School North in Indiana, one girl asked why Mauthausen concentration camp still exists. “Couldn’t they use it again to murder people?” she asked.

I showed the students a picture of Mauthausen, where there is now a memorial. “This is where history happened,” I said. “If we get rid of the evidence, we might forget.”

I talked about the recorded testimonies at Yad Vashem, the Nuremberg trials (at which Nazi leaders were prosecuted after the war), the physical artifacts, all of which can be viewed in various Holocaust museums and camps. Students in Germany can’t graduate from high school without visiting a concentration camp.

At the United States Holocaust Memorial Museum in Washington, a 12-year-old girl told me about her own research, interviewing her grandparents who met each other at Auschwitz. After the liberation, they immigrated to Canada. I told her about international search agencies that can help with documents she had been seeking. She said she wants to get the facts straight.

I’ve learned a lot talking to these students. They aren’t too young. I’ve learned to appreciate the word “l’dor vador,” Hebrew for “from generation to generation,” a fundamental tenet of Judaism, meaning passing it on.

I’ve also learned that memory is something you DO. When you remember, you recall; you tell a story. Storytellers are witnesses, but we’re also custodians of memory. And we must keep telling our stories to remember.