Icek (or Itzhak) Lichtmann was an inmate of the Sobibór Camp. In a deposition of 18 December 1945, he located the (meaning one) gas chamber at a distance of 200 m away from the camp. After the murder, the floors opened, and the bodies were discharged into carts below, which brought them to mass graves. In total, about a million people were allegedly killed at Sobibór.
His claims are rejected as false by the orthodoxy, who insists on several gas chambers in a building inside the camp, which did not have collapsible floors with carts underneath. The corpses were instead taken out of the chamber manually, sideways through a normal door. Furthermore, only about a quarter million victims are said to have died in that camp.