Otto Frank survived his internment in Auschwitz. After the war ended, he returned to Amsterdam in June 1945 where he was sheltered by Jan and Miep Gies as he attempted to locate his family. He learned of the death of his wife, Edith, in Auschwitz, but remained hopeful that his daughters had survived. After several weeks, he discovered Margot and Anne had also died. He attempted to determine the fates of his daughters' friends and learned many had been murdered. Sanne Ledermann, often mentioned in Anne's diary, had been gassed along with her parents; her sister, Barbara, a close friend of Margot's, had survived. Several of the Frank sisters' school friends had survived, as had the extended families of Otto and Edith Frank, as they had fled Germany during the mid-1930s, with individual family members settling in Switzerland, the United Kingdom, and the United States.