In November 1941, German authorities began construction of a killing center on the site of a former labor camp in southeastern occupied Poland. The second German killing center, Belzec began operations on March 17, 1942. Between March and December 1942, the Germans deported approximately 434,500 Jews and an undetermined number of Christian Poles and Roma (Gypsies) to Belzec, where they were murdered. Most of the victims were Jews from the ghettos of southern Poland. The Germans also deported German, Austrian, and Czech Jews to Belzec.
Authorities at the killing center consisted of a small staff of German SS and police officials and a police auxiliary guard unit composed of former Soviet prisoners of war and Ukrainian or Polish civilians. A narrow enclosed path called the "tube" connected the killing center's two sections. The area where mass murder took place included gas chambers and burial pits. Boughs woven into the barbed-wire fence and trees planted around the perimeter camouflaged operations inside the camp.
Trains of 40 to 60 freight cars, with 80 to 100 people crowded into each car, arrived at the Belzec railway station. Twenty freight cars at a time were brought into the camp. Arriving Jews were ordered to disembark. German SS and police personnel announced that the Jewish deportees had arrived at a transit camp and were to hand over all valuables. The Jews were forced to undress and run through the "tube," which led directly into gas chambers deceptively labeled as showers. Once the chamber doors were sealed, carbon monoxide was funneled into the gas chambers, killing all those inside. The process was then repeated with deportees-men, women, and children-in the next 20 freight cars.
Groups of prisoners selected to remain alive as forced laborers removed bodies from the gas chambers and buried the victims in mass graves. Other prisoners were forced to sort the victims' possessions and clean out freight cars for the next deportation. Camp staff periodically murdered these forced laborers, and replaced them with newly arrived prisoners. In October 1942, German SS and police personnel, using groups of Jewish prisoners, began to exhume the mass graves at Belzec and burn the bodies on open-air “ovens” made from rail track. The Germans also utilized a machine to crush bone fragments into powder. By late spring 1943, the camp was dismantled. During June 1943, the remaining Jewish prisoners were either shot in Belzec or deported to the Sobibor killing center to be gassed. After Belzec was dismantled, the Germans ploughed over the site. Soviet forces overran the region in July 1944.