David Nencel was born into a religious Jewish family in Rypin (Poland) in 1916. In December 1942, he was deported to Auschwitz. He survived and was liberated from the Mauthausen satellite camp Ebensee in spring 1945. In Auschwitz, the SS had put him into the Special Squad (Sonderkommando): prisoners who were forced to work at the crematoria and gas chambers. Speaking in 1996, he describes the uprising of the Special Squad on 7 October 1944 (his numbering of the Auschwitz-Birkenau crematoria differs from the standard one).
Source: United States Holocaust Memorial Museum