On November 2, 1942, he was deported, as were all Jews then living in Lunna, as well as neighboring towns, to the Kielbasin (Kolbasino) transit camp (Transitlager or Sammellager).
On December 5, he and all his Jewish townsfolk (numbering approximately 1,500) were forcibly marched from the Kielbasin transit camp to Lososno, Poland, where they boarded a train bound for, as he later discovered, Auschwitz.
[2] After "selection" at Auschwitz-Birkenau, his family members as well as all women and children, and most of the men who were on the transport, were immediately sent to the gas chamber and murdered.
Shortly afterward, Gradowski and several others from the transport who survived the “selection” were sent to work in crematoria as part of the Sonderkommando slave labour unit.
[3] In order to bear witness for future generations, Gradowski wrote a secret diary, in Yiddish, describing his life and the camp.