Marian Turski, a Holocaust survivor who returned to his native Poland after World War II to give voice to fellow victims of the Nazis and their collaborators, warning the world in writings and speeches about the dangers of indifference to racial and ethnic injustice, died on Feb. 18 at his home in Warsaw. He was 98.

His death was announced by the Polin Museum of the History of Polish Jews, which he had helped to establish and whose board he had chaired since 2009.

Speaking in 2020 at the 75th anniversary of the liberation of the Auschwitz-Birkenau concentration camp in German-occupied Poland, where he was shipped from the Lodz ghetto when he was a teenager, Mr. Turski sounded an alarm about what he called “a huge rise in antisemitism.”

“Auschwitz did not fall from the sky,” he said in a Polityka magazine podcast. “It began with small forms of persecution of Jews. It happened; it means it can happen anywhere. That is why human rights and democratic constitutions must be defended.”

“The 11th Commandment is important: Don’t be indifferent,” he asserted. “Do not be indifferent when you see historical lies. Do not be indifferent when any minority is discriminated. Do not be indifferent when power violates a social contract.”

He added: “If you are indifferent, before you know it another Auschwitz will come out of the blue for you or your descendants.”