The Warsaw Ghetto Uprising began on April 19, 1943. It was unique because all the Ghetto Jews were involved this time, in contrast to the few who took part in the "small" uprising on January 18, 1943. The Jews believed that the Germans had retreated because of the JFOs uprising. The fighting organization became the informal leadership of the Ghetto from that moment on. They worked during the day and at night, fortified bunkers in preparation for the end of the Ghetto.
The JFO learned how to fight: don't meet the well-armed and well-trained Germans face-to-face. Between the two uprisings, the JFO and the Jewish Military Organization [Zydowski Zwiazek Wojskowy - ZZW] divided the Ghetto into military sections and concentrated their efforts in the acquisition of arms and preparation of Molotov cocktails.
After three days of fighting, the Germans began to systematically torch the Ghetto. The JMO [ZZW] commander Pavel Frenkel and his remaining comrades, who escaped through a tunnel they dug in the Muranow district, were informed on, captured and murdered.
The last of the JFO fighters hid in the bunker at Mila 18. Some managed to escape to the "Aryan" side through the sewers and the rest, under Mordechai Anielevich's command, took their own lives on May 7th when the bunker was discovered.
Until the 16th of May, the SS continued their "war against the bunkers", as Stroop termed the refusal of the Ghetto fighters to surrender..
In total 16 German soldiers were killed and 300 wounded in the military action to put down the revolt. The significance of the revolt was not in the numbers however. All those in the Ghetto when the revolt began were slated to kiled at Treblinka, instead of being killed killed quitely, those who organized the revolt showed that Jews could and would fight back.