The use of gas proved to be a highly effective way of killing people in large numbers. Within less than a year the Germans managed to murder approximately 80% of the Jews living in the General Government territory. Hence the final phase of Operation Reinhard began, involving the liquidation of the so-called ‘residual-ghettos’ and forced labour camps. It reached its peak during an action codenamed Erntefest (harvest festival), which took place in the Lublin district on 3‒4 November 1943. In that brief period about 42,000 Jews were killed, and almost 18,000 just in one day. This was the largest single German massacre of Jews in the entire Second World War exceeding even the Babi Yar massacre. The order to immediately liquidate the Jewish population was a consequence of the armed revolt in Sobibór. For this reason, it was decided that all the extermination camps on the eastern territories of the General Government were to be closed. It is estimated that during the war, the extermination camps killed approximately 3 million Jews.
