Trucks to Camouflage the Noise of Gassing

I visited the Auschwitz-Birkenau camp during Winter 1997 (…) Near the Auschwitz-Birkenau gas chambers one may still see an old truck, the engine of which was activated by the Nazis in order to prevent the inmates from hearing the shrieks of their fellow comrades …

From the February 29, 2000, Journée nationale des Justes de France: