The dentist Jonas Bak lived in Wilna (Vilnius, Lithuania) with his wife Mitzia and son Samuel Bak. Shortly after German troops invaded in 1941, Jonas Bak was put into a labor camp outside the city, digging peat. He managed to escape in the fall of 1941 and hid in a Benedictine convent in Wilna, where his wife and son had previously found refuge. When the Germans searched the convent, Bak and his family escaped. With nowhere else to hide, they moved into the Wilna ghetto.
Jonas Bak was soon put into a nearby labor camp and had to work in the Wehrmacht’s Army Vehicle Pool (HKP). Shortly before the Jews were deported from the ghetto in March 1943, he brought his family into the HKP camp. As murders became increasingly frequent in the camp, Jonas Bak arranged Mitzia and Samuel’s escape. They managed to get away, while Jonas Bak himself remained in the camp. When the HKP camp was evacuated in July 1944 he was taken to Ponary, and shot dead there.