By the end of the war, Samuel and his mother were the only members of his extensive family to survive. His father, Jonas, was shot by the Germans in July 1944, only a few days before Samuel's own liberation. As Bak described the situation, "when in 1944 the Soviets liberated us, we were two among two hundred of Vilna's survivors--from a community that had counted 70 or 80 thousand." Bak and his mother, as pre-war Polish citizens, were allowed to leave Soviet-occupied Vilnius and travel to central Poland, at first settling briefly in Łódź. They soon left Poland and traveled into the American-occupied zone of Germany. From 1945 to 1948, he and his mother lived in displaced persons camps in Germany. He spent most of this period at the Landsberg am Lech DP camp in Germany. It was there he painted a self-portrait shortly before repudiating his Bar Mitzvah ceremony. Bak also studied painting in Munich during this period, and painted "A Mother and Son", 1947, which evokes some of his dark memories of the Holocaust and escape from Soviet-occupied Poland.