Gas chamber
A Gas chamber is a means of executing human beings whereby a poisonous gas is introduced into a hermetically-sealed chamber. When the condemned breathes this gas, death follows.
Capital punishment
Gas chambers have been used as for capital punishment in the United States in the past to execute criminals, especially convicted murderers, but this is done less often today.
In the United States, the punishment was (and still is) instituted individually and publicly, behind the protective glass of a gas chamber, in full view of accredited journalists, legal and medical experts, and the prosecuting side. The gassed individual can see the poison, and is advised to take a deep breath after the gas is released, to speed unconsciousness rather than prolonging death. The gas used is hydrogen cyanide, and death from it is painful and unpleasant.
Genocide
More notoriously, gas chambers were used in the Nazi Third Reich during the 1930s a part of a public euthanasia program aimed at eliminating physically and intellectually disabled people. At that time, the preferred gas was carbon monoxide. Later, during the Holocaust, gas chambers were modified and enhanced to accept even larger groups as part of the Nazi policy of genocide against Jews, Gypsies, homosexuals, Jehovah's Witnesses and others. These also began using carbon monoxide, often provided by the exhaust fumes of cars and trucks, though later experimentation found that Zyklon B gas was more efficient. The Nazi gas chambers in operation in at least eight camps and mobile vans were used to kill several million people between 1941-1945.
The American method may be contrasted with the method used in the Nazi Germany, which was instituted en masse and secretly. The victims were apparently unaware of their fates; they died in the belief that they were entering the chambers to be cleaned and deloused.
Controversy
However, there is an ongoing controvery about whether or not the condemned knew what would happen to them. Some argue that they did know, but elected to submissively meet their fate rather than attempt to confront the armed guards. While it is true that they vastly outnumbered the guards in proportions of 1:100 or more, the condemned were unarmed, often malnourished, emaciated, and ill, and were concentrated in areas where the general populace was either hostile or indifferent to their fates, or were too fearful of their own lives to aid any escaped prisoners. Some prisoners called Sonderkommandos were forced to help the Nazis murder their fellow prisoners by leading prisoners to the gas chambers and disposing of the bodies.
Some Jews did resist, most notably in the 1944 Sonderkommando uprising at Auschwitz, during which one of the gas chambers was destroyed.
See also: Extermination camp