Survivors of the Auschwitz concentration camp were gathering at the former Nazi death camp Monday to commemorate the 75th anniversary of its liberation. More than 200 survivors were expected to attend, ranging in age from 75—a woman who was born in the camp—to 101. For some, it could be their last visit to the place where they were incarcerated by Adolf Hitler’s regime during World War II. Survivors drew on their memories ahead of the event. Benjamin Lesser, a 92-year-old Polish-born Jew whose family was sent to Auschwitz in 1944, said: “The Holocaust was sponsored and was okayed by a government. Not only did they allow it to happen but they enforced it and encouraged regular people to become killers... I have returned so that I don’t forget any of the details of what happened to me, so I can keep the memories alive, and stop the world from acquiring amnesia.” An international guest list will join the survivors at the remains of the camp, but top world leaders, who attended a memorial event in Jerusalem last week, will not be there. Auschwitz was liberated by Soviet troops on Jan. 27, 1945.