Copyright © United States Holocaust Memorial Museum, Washington, DC

The Germans renew deportations from the Warsaw ghetto. This time however, they encounter resistance from the ZOB (Jewish Fighting Organization; Zydowska Organizacja Bojowa). The early morning roundups take the ZOB organization by surprise, and individuals take to the streets to resist the Germans. Other Jews in the ghetto retreat into prepared hiding places. The Germans, expecting the expulsions to run smoothly, are surprised by the resistance. In act of retaliation they massacre 1,000 Jews in the main square on January 21, but suspend further deportations. The Germans were able to deport or kill 5,000-6,500 Jews. Encouraged by the results of resistance actions, the Jews in the ghetto plan and prepare a full-scale revolt. The fighting organization is unified, strategies are planned, underground bunkers and tunnels are built, and roof-top passages are constructed. The Jews of the Warsaw ghetto prepare to fight to the end.