Stefan Szuberski was a member of the youth organization of the socialist party in Poland. He helped the Jewish Fighting Organization escape the burning ghetto for the forests of Lomianki and Wyszkow where they continued fighting with partisan detachments. A Pole who saw him near the sewage pipes on the Aryan side reported him. He was found in a restaurant and shot dead by the Germans.
Source: Dor, Danny, Ed. Brave and Desperate. Israel: Ghetto Fighters' House Museum, 2003.