In 1944, Rudolf Vrba and Alfred Wetzler escaped from Auschwitz-Birkenau concentration camp. Their harrowing testimonies and detailed sketches of the camp’s mass extermination practices exposed the “dark heart” of Nazi-occupied Poland.
The prisoners in Auschwitz-Birkenau who knew best what happened at the gas chambers and the crematorium were members of the so-called Sonderkommando. These were prisoners who were forced by the SS to assist in the killing and cremation at the crematory itself.
Rudy and Freddie felt that they needed to have facts that would convince people that this really is happening and it was their idea to write a report that could be distributed and shown as evidence. Vrba and Wetzler wanted to include as much granular evidence as they could in their report and that included some drawings.
Auschwitz is a massive place and it builds up over time and in different ways. So the first camp is Auschwitz I, which opens in 1940. Later they add Birkenau a few miles away which is where the gas chambers in the crematorium are located. This is an approximate sketch of the dark heart of Auschwitz main camp and Birkenau, but this is one of the gas chambers and crematoria that the SS constructed in Birkenau. It's striking how much Vrba and Wetzler got right about the layout of the camp the mechanics of mass extermination and even down to the names of individual prisoners.