This video says about itself:
Escape from Sobibor: 1987
During WWII, the death camp at Treblinka had an escape, causing the Commandant at a similar camp in Sobibor to vow that his camp would never experience the same thing. But those who were its captives, the Jewish laborers that had been spared from the ovens, knew that they were on borrowed time and that their only hope was to escape… the only question was how to do it. However, because the Germans would kill an equal number of others whenever a group attempted to escape, the captives knew that if ever an escape was tried, all 600 prisoners in the camp would have to be included… logistically precluding any ideas about tunnels or sneak breakouts. Indeed, to have such a mass escape could only mean that the Ukrainian guards and German officers would have to be killed, which many of the Jews felt simply reduced themselves to no better than their captors… thus making it a struggle of conscience. And therein lies the story, with the film being based on a factual account of what then happened at that Sobibor prison.
The above film is public domain. I have posted this in good faith with the information and records available to me online.
Translated from NOS TV in the Netherlands:
Update: Wednesday Sep 17 2014, 21:03
Researchers have found the exact location of the gas chambers of Sobibor, one of the nazi death camps in Poland. The study lasted eight years. The researchers, including a Dutch archaeologist, called the find important for the study of the Holocaust.
After an uprising in October 1943 the Germans closed the camp and they demolished the buildings to delete the traces of their crimes. Then a woodland grew over it.
The gas chambers were in use from April 1942 to October 1943. The nazis have killed at least 170,000 Jews there.