After 6 months in Auschwitz, the largest  concentration camp, he got sent to Auschwitz 2-Birkenau. The work, excavating  the bodies of prisoners that had already been murdered and buried, at Birkenau, almost took Vrba’s life. Thankfully a Viennese prisoner, trusted by the SS, transferred him to a store room, where the belongings of the dead had been. 

He had been working with Alfred Wetzler, to escape Birkenau. One the eve of Passover, April 7 1944, "Vrba and Wetzler sneaked into a previously used hideout sprinkled with gasoline-soaked tobacco to prevent the dogs from sniffing them out". The camp authorities thought they had already escaped, so they stopped paroling that area, where Vrba and Wetzler were. They were ready to escape. They knew that no one in the outside world would help them with their bald head and striped pajamas. After 11 long days of walking and hiding, the two men, made their way back to their home country, Slovakia. Vrba warned Jews "that preparations were being made for the murder of nearly 800,000 Hungarian Jews. They also suspected that 3,000 Czech Jews, in the Auschwitz-Birkenau 'family camp' would be gassed within a few months."

Vrba and Wetzler had a mission after they escaped, it was to warn the world about that awful place.

Vrba wrote books about his escape, and life in the camp. His escape was both beneficial for him and the Jews.