Fela Katz (My grandmother’s sister) was born on May 10, 1923, in Sosnowiec, southern Poland, the daughter of Leon Katz and Bluma Ganczel. During World War II, Fela Katz was one of the young women active in the Jewish underground in the Zagłębie region, at the heart of one of the Jewish resistance networks operating under the German occupation. Several important Jewish youth movements operated in Sosnowiec during the occupation: Hashomer Hatzair, Zionist Youth, Dror and Gordonia. The young people who belonged to these movements did not limit themselves to trying to survive. They attempted to establish an underground network, transmit information, organize hiding places, smuggle people out, and find ways to get Jews out of the area before they were sent to their deaths. Fela Katz was part of this circle. Her name appears alongside those of young people who later became central figures in the Jewish resistance in the region, including Zvi Donski, Kasia Shansar, and Shmuel Ron. Fela’s own testimony has been preserved in the archives of the Jewish Historical Institute in Warsaw, and it serves as a source for historical research on the Jewish underground in Sosnowiec. The underground’s activities were especially dangerous. The young activists had to contend not only with the Germans, but also with the surveillance mechanisms within the Jewish community itself. They held secret meetings, transmitted information, organized hiding places, and attempted to establish escape routes. Within this network there was also a connection with Mordechai Anielewicz. Anielewicz was one of the leaders of the Jewish resistance in Poland, and he worked to establish connections between different underground centers. In Sosnowiec, the underground newspaper Przełom was published, and Anielewicz was connected with the initiative behind its publication. Fela Katz was connected to the underground circle in which this activity took place, and her testimony is used in historical research dealing with the Jewish resistance network in the region.