The majority of deaths during the single largest murder campaign of the Holocaust, called Operation Reinhard, occurred during a single three-month period, a new study reveals. Not only does this study indicate that the murder rate during Operation Reinhard has previously been greatly underestimated, it also provides new insights into the profound efficiency of Nazi death camps and the systematic manner in which Jewish communities were murdered. During the Nazi-German campaign to eradicate Jews during the second World War, a great portion of the Holocaust killings occurred during Operation Reinhard, which lasted from 1942 to 1943. However, detailed records of the killings were largely destroyed by the Nazis, making it difficult to investigate how quickly the genocide was carried out. Deutsche Reichsbahn, the German National Railway, played a critical role in transporting millions of Jewish victims to the death camps, and the "special trains" that transported the victims were kept on strict time schedules. Yitzhak Arad, an Israeli historian specializing in the Holocaust, compiled Reichsban data on 480 train deportations from 393 Polish towns and ghettos to three key death camps - Belzec, Sobibor, and Treblinka - during Operation Reinhard and estimated the number of victims on each transport. Here, using Arad's data, Lewi Stone estimated the rate at which the Nazis killed Jews during Operation Reinhard, showing that most of the murders occurred in only three months - August, September and October 1942. Of the 1.7 million victims of Operation Reinhard, 1.32 million (78%) were murdered during these three months, or about 15,000 murders per day, every day. This finding implies that roughly 25% of all Holocaust victims were murdered during these three months of Operation Reinhard in 1942. Compared to the 1994 Rwanda genocide, which has been suggested as the most intense genocide of the 20th century, the murder rate during Operation Reinhard was 83% higher, according to Stone. Stone estimates that the Nazi's murder campaign could have continued at this pace had there had been more victims living in Germain-occupied Poland, and instead the murder rate tapered off in November 1942 as a result of there being essentially no one left to kill, Stone says.