Jack was born on March 3, 1943, in Nyiregyhaza, Hungary. His father was a furniture manufacturer, and his mother was a homemaker. The family lived a normal life until 1944, when the Nazis invaded Hungary. At that time, there were 750,000 Hungarian Jews, but by April 1944, they were rounded up and placed in the yard of the synagogue, which had been converted into a ghetto.