In the afternoon of 21 April 1945, prisoners were ordered to pass to the building of tailor and shoe shop located in the South-Eastern part of the camp. At the same time, women were taken toward the central part of the camp and killed. The camp clerk, Mićo Anić from Osijek, provided the numbers of prisoners in the building to Ustashas – exactly 1,073 of them. Their number was reduced over the night for several prisoners hanged themselves out of panic and fear. While detonations of explosives used to pull down camp buildings echoed through the night, a group of some ten prisoners separated in one room, aware that something needed to be done. Relying on the factor of surprise, that was going to be achieved when all of them together started rushing outside the building through the doors and windows, they decided to try to break out of the camp. Ante Bakotić, the leader of the work group of chemists, was elected the leader, who was going to give a sign to start the outbreak.

On Sunday, 22 April 1945, at 09:50 hrs, the sign was given for outbreak. People, armed with bricks and boards, stormed the building door. When the door broke around 600 prisoners ran out of the building, while the rest did not participate in the breakout due to illness, infirmity and despondency. The guard at the building door was run over. The guards located around the building were overpowered too, and the fight continued at the camp’s Eastern gate. There were bunkers there from which Ustashas killed prisoners with machine gun fire and hand grenades. The bunker next to the gate was taken care of by Mile Ristić with a machine gun grabbed from Ustashas who thus enabled prisoners to leave the camp confines. What was important, too, was that prisoner Edo Šajer climbed a pillar cutting off telephone lines, and Ustashas were not able to call for backup. After passing through the camp gate they needed to decide which direction to take to escape. Most of the prisoners saved their lives fleeing towards the East in the direction of the Košutarice village. They needed to bypass bunkers on their way there just like the guards providing external defence for the camp. Those that tried to save themselves by swimming across the Sava River were an easy target for Ustashas who fired rounds at them from the river bank. Moreover, the river was swollen and cold and many of them drowned. A total of 90 prisoners saved themselves who managed to survive until the arrival of Yugoslav Army units who were passing through Slavonia heading towards the West.

In the evening of the same day, breakout from the Camp IV Kožara took place, too. A total of 12 Kožara prisoners manged to survive.