"Jack was born in Poland in 1928 and was sent to a Jewish ghetto in 1939 after the Nazi occupation. He was sent to the Auschwitz death camp in 1944 where he was examined and then transfered to a labor camp before being freed by the U.S. Army in April 1945.
In 1993, Jack was a co-founder of the United States Holocaust Memorial Museum in Washington, D.C. Its collections contain more than 12,750 artifacts, 49 million pages of archival documents, 80,000 historical photographs, 200,000 registered survivors, 1,000 hours of archival footage, 84,000 library items, and 9,000 oral history testimonies."

I myself have met an Auschwitz survivor who also had an absolutely indomitable spirit. I guess what doesn't break you makes you stronger.
RIP Jack.