John Adler, son of Charlotte and Salo Adler, was born Hans Gunther Adler on September 17, 1923 in Goldberg, Germany. John grew up in a reform Jewish household and was an only child. John went to a local elementary school, and attended a Jewish middle school after moving to Breslau. As a student, he had academic goals of becoming an artist. On November 9, 1938, John witnessed two synagogues in his town burn to the ground. Following this night, his family knew they needed to make quick decisions about leaving Germany. John’s parents escaped to Shanghai, but John did not want to. Instead, in 1939, he went to Israel with the Zionist Youth Organization. Soon after, John joined the British Army and worked in the Royal Engineers branch from 1941 to 1946. After the war, he moved to the United States in 1948 where he was able to reunite with his parents. John settled in Los Angeles, where he met and married a woman named Ruth and had his daughter, Eileen, and two grandchildren, Matthew and Michael. John was interviewed on September 6, 2018, in Los Angeles.

John Adler's testimony was recorded in 2018