The brutality of Cambodia's Khmer Rouge regime is documented in Rithy Panh's documentary, S21: The Khmer Rouge Killing Machine. S21 was a notorious detention center, an abandoned suburban schoolhouse used by the Angkor (the Communist Party organization) for the imprisonment and torture of thousands of innocent citizens. Prisoners were tortured until they confessed to false crimes, and were also ordered to incriminate others. Of the approximately 17,000 prisoners who were interred there, about seven survived. Panh interviews two of the survivors, Vann Nath and Chum Mey. While Mey can barely bring himself to speak of the horrors he endured, including the loss of his family, Nath agrees to return to the prison, which is now the Tuol Sleng S21 Genocide Museum, and discuss his ordeal. Panh also brings back several of the Khmer Rouge personnel, who committed atrocious acts on behalf of the regime, many while they were still teenagers. The guards and interrogators give a horrific tour, reenacting their treatment of the prisoners, and going through the regimes detailed records, including photographs, to refresh their memories of the horror they took part in. Panh allows Nath to confront them about their actions, but most of them claim that they themselves were also victims, indoctrinated in the regime's poisonous ideology, and too afraid for their own safety to show any compassion for their victims. Panh himself was imprisoned at a Khmer Rouge labor camp as a teenager, before escaping to Thailand in 1979. S21: The Khmer Rouge Killing Machine won the Prix François Chalais at the 2003 Cannes Film Festival, and was also selected for the 2003 New York Film Festival.