The Nazis used poison gas to murder millions of human beings whom they deemed undesirable. One of several methods used was the gas van. Such vans were first deployed in 1940 in the "euthanasia" operation. Hitler delegated the "euthanasia" operation to Reichsleiter Philip Bouhler, Dr. Karl Brandt, and several doctors of their choice. The targets were several German population groups: the mentally ill or retarded, the chronically ill, and criminals. At first, the murders were carried out in fixed, sealed chambers, into which carbon monoxide gas was pumped from metal canisters. In addition, some were killed by lethal injections and by shooting. In 1940, an experiment using gas vans was conducted in Kochanowka, near Lodz, in the murder of mentally ill children.
Between 70,000-100,000 people were murdered in "euthanasia" operations. Experts who became experienced with poison gas and mass murder in this program were later employed between 1941 and 1942 in the occupied eastern areas, where they engaged mainly in murdering Jews.
