Walter Frankenstein, who with his family hid from the Nazis for more than two years by taking refuge in abandoned buildings, cars, forests, craters, brothels, and wherever they could survive, died on April 21 in Stockholm, where he had lived since 1956. He was 100.

To support his family, he worked as a mason, which brought him into contact with Adolf Eichmann, a pivotal architect of the Final Solution, who threatened him as he did plastering work in Eichmann’s o residence. “One speck and you’re in Auschwitz tomorrow,” he recalled Eichmann saying.

In later life, the Frankensteins regularly visited Germany, where Mr. Frankenstein spoke at schools and museums. Klaus Hillenbrand, Mr. Frankenstein’s biographer, said that “keeping the memory of the Shoah was a mission for him.”