Holocaust Survivor Couldn't Talk About It for 50 Years. Biden Listened for 90 Minutes in the Oval Office

In the first 50 years since she survived the Auschwitz extermination camp in Poland, Bronia Brandman never spoke of the terror she faced during the Holocaust — not even with her children.

"Not a word to anyone," Bronia, now 90, tells PEOPLE. "I didn't think people would comprehend what happened."

She still didn't want to discuss it when she was being trained as a volunteer for the Museum of Jewish Heritage in Manhattan in 1996. But then a fellow volunteer spotted "52643" tattooed on her left forearm — the Nazis forced Jewish prisoners to get tattoos as a form of identification — "and kept on bugging me to tell my story," she says. "I said, 'Absolutely not.' But I was tired of her bothering me, so I took a tranquilizer and told my story to the group [at the museum]. They were amazed."

Since that day in 1996, the retired New York City school teacher has shared her story hundreds of times — in an HBO documentary, to school children who survived the Sandy Hook massacre and, most recently, during a 90-minute private chat with President Joe Biden in the Oval Office on Thursday, Jan. 27, International Holocaust Remembrance Day.

"He made us feel very comfortable," says Bronia. "Very like friends to friends talking, and we were very impressed."

She's motivated to talk to bring attention to the recent surge in anti-Semitism and anti-Semitic violence, which she calls "very scary." She was "horrified" last week when Russian forces invading Ukraine bombarded the area near the Babyn Yar Holocaust Memorial Center in Kyiv, where the Nazis killed 34,000 Jews within 36 hours in 1941.

"I hope that by hearing my story of the horrors of the Holocaust, people remember the most horrible evil can start with words," she says. "I also hope that you can hear the power of each person to do good and to change the world for good."

As a young girl, Bronia Rubin and her five siblings — the children of a hardware store owner — lived comfortably in Jaworzno, Poland. She was 8 when the Nazis invaded her town in 1939.

The family fled to another town called Mielec but found no safety there. "The Germans came in on the very first night. We heard horrible, scary voices screaming, 'They're Jews. Get out!'" she recalls. "They selected the men, marched them to the synagogue and burned them alive.

"And then they went to this house and butchered Jews and hung them on meat hooks," she continues. "I learned what the Germans had in store."

Spared at that time, they eventually made it back to their hometown. Then her older brother, Mendek, was taken to a labor camp before the Nazis ordered all Jews in town to the school yard in August of 1942.

"My father sensed that this was the end," says Bronia, who was 11 at the time. Her older sister, Mila, and two baby sisters were already in hiding; Bronia and another brother came with him to the yard.

"We realized we are never returning home," she recalls. "My mother whispered to me to run. I knew that if I ran there would be bullets coming in my direction. So I walked out slowly."

Bronia never saw her parents or brother again. "They were sent to Auschwitz and were murdered in the gas chambers," she says.

Soon after reuniting with her three sisters, they hid until the Nazis discovered them and packed the girls into a railroad car bound for Auschwitz in August of 1943.

Some 1.3 million people — including 1.1 million Jews — were sent to Auschwitz, the largest of six Nazi concentration camps. Over 960,000 Jews were killed in Auschwitz; in total, the Nazis killed over 6 million Jews.

Once there, the sisters faced Josef Mengele, the infamous Nazi doctor who performed medical experiments on Jews. He pointed right for those who would live — women and men who could work at the camp. Her sister Mila, then 20, was among them.

"He pointed the three of us, my two baby sisters and me, to the left, which we knew was the gas chamber," she says.

"Without thinking, in an instant, I didn't want to die, I ran to my sister's line," Bronia says. "Nobody stopped me. But that meant that my two baby sisters were going to the gas chamber alone. That put my heart into stone."

Bronia and Mila were stripped naked and had their heads shaved and arms tattooed. Their hunger "was indescribable" and death always hovered. "If you don't go to the gas chamber today you would go to the gas chamber the next day or the next day," she says. "You're never going to come out of Auschwitz alive — only in smoke, through the chimney."

When Mila came down with typhus, she was moved to a barrack for the sick to die. Bronia followed. "I did not want to part from Mila," she says.

Soon, a Jewish nurse, Bozenka Teinerova, told Bronia that all the sick were going to the gas chamber the next day.

"She singled me out to save me. She risked her life," says Bronia.

She recalls wondering how she was going to say goodbye to her sister.

"I wasn't able to face Mila," says Bronia. "They took Mila to the gas chamber the following day."

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Bozenka hid Bronia in a barrack for Christians and later helped her evade going to the gas chamber when Mengele picked her number to perish. At the end of World War II, as the Soviets were days away from arriving at Auschwitz to liberate the prisoners, Bronia was forced on a "death march" with nearly 60,000 others from the camp to Germany. Brozenka again saved her life.

"If you slow down, you were shot. I was slowing down," Bronia says. "Bozenka grabbed me and carried me. Where did she get the strength? She risked her life again." About 15,000 would die along the march.

The pair stayed together in camps in Germany until the Allies liberated them in May of 1945. "Where was I going to go, and to whom?" says Bronia. "Everybody was dead."

Bozenka stayed with Bronia, and the duo made their way to the nurse's family farm in Slovakia.

"She always treated me as if I was her child," says Bronia. (She kept in touch with Bozenka — who came to the U.S. in the 1970s — until her death a few years ago.)

After a cousin found Bronia, she was reunited with her older brother, Mendek, who survived years in the labor camps. At 15, she came to the U.S. and settled in Borough Park, Brooklyn, at the home of her cousin, Simon. She's lived in Borough Park ever since.

Despite not knowing English, Bronia quickly earned her high school degree, married Ephraim Brandman in 1952 and had two daughters. (Today she is a grandmother and great-grandmother of 4).

After earning her degree at Brooklyn College and a master's in teaching at Adelphi, she taught English as a Second Language in New York City schools until retiring in 1996.

Throughout all these years since the Nazis killed most of her family — the only survivors were Bronia and her brother — the trauma of the Holocaust has left her unable to cry. Even the death of her younger daughter in 1992 could not give her a tear.

"I forgot that I had parents once, that I had siblings, that I had a home, I forgot it," she says. "I was not human."

By finally sharing her story, Bronia has become an "extraordinary hero to me," says her daughter Etta, 65, an attorney. "It is speaking up in the most painful way possible to make it real."

After speaking to students who survived the mass shooting at Sandy Hook Elementary School that left 26 dead, one wrote to her: "...your story of resilience in the Holocaust has helped me to open up about my experiences in the December 14 shooting in Sandy Hook in 2012. I have been angry and resentful at [the murderer] for so long and you have started me on my path to truly healing myself of my PTSD."

Her message is one that also resonated with Biden. "It was my greatest honor to meet with you," the president wrote in a letter, "you have so much to be proud of!"