Story highlights The biggest mistake that was made during the Holocaust was that people didn't speak up, says Sonia K, a survivor

We must stand against anti-Semitism and racism, or we could find ourselves repeating a regrettable history, she says

Sonia K. is a Holocaust survivor who was forced to live in the Warsaw Ghetto before being taken to Majdanek , Auschwitz, Ravensbruck, and Malchow concentration camps. She was liberated in April of 1945 by American soldiers in Mittenwald, Germany. Sonia went on to have a family and open the first Jewish business in Mittenwald after the war. She currently lives in Brooklyn, New York, where she volunteers with Hadassah, Amit and State of Israel Bonds. Sonia is a client in Selfhelp Community Services' Brooklyn Holocaust Survivor Program. Selfhelp is a nonprofit that supports seniors and at-risk populations in New York, including Holocaust survivors.

(CNN) When I came to the United States in 1949 after the Second World War, the world had just witnessed the horrific culmination of centuries of anti-Semitism: the indefensible murder of 6 million Jews.

Sonia K.

In the 1930s, we all believed that nothing like the Holocaust could ever happen, and for the past seven decades, we've said that nothing like it can ever happen again.

But the last few months have felt like 1938 all over again, the year when Kristallnacht -- a night when riotous violence against Jews swept through Nazi Germany — announced the brutal persecution to come. I'm scared -- not for myself, but for my children, my grandchildren, and all children.

Some might dismiss the violence in Charlottesville, Virginia, as the actions of unhinged or fringe individuals. Others might believe President Trump's comments equating neo-Nazi and anti-fascist protesters are merely reflective of his often exaggerated speech. However, Holocaust survivors know all too well that what starts as a protest or an offhand comment can turn into something far worse. In the 1930s, the warning signs of what was to come were similar to the events unfolding today -- and society didn't listen. We can't afford to make that mistake again.

Sonia K. and her husband Josef.

I was born in Poland and forced to live in the Warsaw Ghetto until mid-1943, when I was taken to Majdanek concentration camp and then Auschwitz. By the time I was liberated in April 1945, I had survived four concentration camps. I met my husband in the Mittenwald camp, and we lived in Germany for four years after the war before settling in Buffalo, New York.

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