What happened exceeded our boldest dreams. The Germans fled twice from the ghetto. One of our companies held its position for forty minutes, while the other one lasted – upwards of six hours… I cannot describe to you the conditions in which the Jews are living. Only a handful will survive. All the rest will succumb, sooner or later. Their fate has been sealed. In almost all of the bunkers in which our friends are hiding one cannot even light a candle at night, for lack of air. Goodbye my friend. Perhaps we will see each other again. The main thing is this: My life’s dream has become a reality. I have seen the Jewish defense of the ghetto in all its strength and glory.
23 [21] April 1943
Mordechai Anielewicz
On the 19th of April 1943, Passover eve, the Germans entered the ghetto. The remaining Jews knew that the Germans would murder them and they decided to resist to the last man.
The invading German forces were surprised by the ferocity of the resistance of the armed groups, and by the perseverance of the ghetto inhabitants, who had fortified themselves in bunkers and hiding places. The fighting outposts of the Jewish Fighting Organization, under the command of Mordechai Anielewicz, were spread out far and wide across the ghetto. The Jewish Military Union fought side by side with the Jewish Fighting Organization; the former concentrated their efforts on the Moranowski square in the north part of the ghetto, and in the industrial area of the brush workshops. After three days of fighting, the Germans understood they would be unable to make the Jews report for deportation as planned. They began systematically setting fire to the ghetto, turning it into a giant firetrap. The blaze was documented by German propaganda photographers, at the initiative of Jürgen Stroop, commander of the S.S. unit that suppressed the Warsaw Ghetto uprising.
by yadvashem.org