The construction of the death camp began on 1 November 1941. The works most likely continued until the turn of March 1942. The camp occupied an area of ca. 7 hectares, the entirety of which was surrounded by a double barbed wire fence. Felled conifers were woven into the fence to mask the interior of the camp. There was a watchtower in every corner. The first group of workers were the inhabitants of Bełżec and the surrounding area – a group of 20 people. They constructed three buildings, unaware of their intended use. Former Soviet prisoners of war from Trawniki also participated in the construction works. On 23 December 1941, local workers were dismissed and replaced by Jews brought from the nearby village of Lubycza Królewska. It was a group of ca. 120–150 people. They completed the final stages of the construction of the camp. In February or early March 1942, they were murdered in the test run of gas chambers. The death camp in Bełżec was the first death camp to feature stationary gas chambers. Initially, Germans used compressed carbon dioxide to kill their victims, but this solution was ultimately replaced with exhaust fumes produced by an engine pulled out of a Soviet tank.
The first two transports of prisoners arrived to the death camp in Bełżec on 17 March 1942. A group of Jews from the Lublin Ghetto was brought to the site in the morning, while in the afternoon they were joined by people deported from Lviv. From that day on, transports continued to arrive to the site almost until mid-December 1942. Deportations were carried out in waves. Displacement campaigns intensified in the summer of 1942, following Heinrich Himmler’s order to complete the liquidation of all ghettos in the General Government. In the short history of the camp, two phases can be distinguished: March-June and July-December. Within several months, at least 179 transports arrived at the camp in Bełżec, 59 of which reached the site in the former period and 120 in the latter.
Transports were generally accepted only during daytime. Trains which arrived late in the afternoon or at night were kept under guard at the railway station.
Over 430,000 people were killed in the camp. The victims were mostly Polish Jews deported from the three districts mentioned above, as well as German, Austrian, Czech and Slovak Jews. Germans murdered most of them without leaving any trace, as no deportation lists were drawn up. Apart from Jews, a relatively small group of Roma people and Poles was murdered in Bełżec.
