I am descended from Leo Sack, brother of Ceclia Sack Zeitlin. She had four brothers and no sisters. Her mother's name was Esther Etil, d. Salant 1894. Esther Etil's father was Arye Leib. Cecelia's father was Avraham Aba (Abel) Sack, 1816-1880, d. Salant. His father was Bezalel Sack. The Sack family tree was done by George Sackheim and includes thousands of family members, going back to the beginning of the 17th c. Our link is tenuous, but very likely.