Aktion T4 was the name for the mass murder by involuntary euthanasia in Nazi Germany's eugenics program based on "mercy killing" and mandatory sterilization. The program started in October 1939 on the orders of Adolf Hitler. The office that had to implement this Sonderprogram worked under the leadership of Philipp Bouhler a German senior Nazi Party functionary who was both a Reichsleiter (National Leader) and Chief of the Chancellery of the Führer of the NSDAP. He was also the SS official responsible for the Aktion T4 euthanasia program that killed more than 250.000 disabled adults and children in Nazi Germany, as well as co-initiator of Aktion 14f13, also called "Sonderbehandlung" ("special treatment") that killed between 15.000 - 20.000 concentration camp prisoners. 

Also appointed as an organiser was Karl Brandt Hitler's personal physician. Trained in surgery, Brandt joined the Nazi Party in 1932. A member of Hitler's inner circle at the Berghof, he was selected by Philipp Bouhler, the head of Hitler's Chancellery, to administer the Aktion T4 euthanasia program. Brandt was later appointed the Reich Commissioner of Sanitation and Health (Bevollmächtigter für das Sanitäts- und Gesundheitswesen). Accused of involvement in human experimentation and other war crimes, Brandt was indicted in late 1946 and faced trial before a US military tribunal along with 22 others in United States of America v. Karl Brandt. He was convicted, sentenced to death and later hanged on 2 June 1948.

The name T4 is derived from the address of their office, Tiergartenstraße 4 in Berlin.

Goal

The goal of the program was to preserve the genetic purity of the Germanic people by systematically murdering people who were disfigured, disabled or suffering from some form of psychiatric illness. Arguments to justify this murder were the in Nazi eyes "meaningless existence" and the "meaningless suffering" of these patients. The purification program was called "mercy killing" because the Nazi doctors saw it as an act of mercy and presented it as the most humane way to put these sick out of their suffering. This thesis belonged to Karl Brandt, Gruppenführer in the SS and Generalleutnant in the Waffen-SS. He was sentenced to death in the Medical Trial, one of the Nuremberg Trials, and later hanged. In addition, there were also economic considerations: those who worked in the care of the disabled could not serve as a soldier or work in the war industry.

Disabled children were separated from their families and taken to special hospitals. The media at the time responded to the fear that within a few years a large part of the German people would be mentally disturbed, reason to act as quickly as possible. The word "euthanasia" was not used in Nazi propaganda, leaving the real intentions of the Nazis (at the beginning) undiscovered. The program was later expanded to include adults, most of whom underwent compulsory sterilization.

Where did it take place

The exterminations took place in:

The involuntary euthanaisa was carried out by gassing, asphyxiation, injections, poisoning, starvation and drug overdoses. The first experiments with gas vans were carried out in March 1940 at the hospital in Kochanowka near Łódź. Soon after, the Nazis conducted further experiments in which they poured carbon monoxide from the exhaust of a truck into a closed room. Many of these exterminations were overseen by psychiatrists Carl Hans Heinze Sennhenn and Werner Villinger. Sennhenn supplied hundreds of brains to Nazi researchers. Werner Villinger conducted experiments on humans before sending them to death. Even before the Holocaust, the first gas chambers were built in Hartheim, where adults in particular were killed with carbon monoxide.

Temporary stop due to pressure from the church

On 18 August 1941, Hitler temporarily halted the program under pressure from Cardinal Clemens August von Galen of the Catholic Church, other churches and families of the victims. More than 70.000 people had already been murdered by then. The German public resistance slowed down but not completely halted; the program was continued in utmost secrecy. Trained troops kept going. Some parts of the program were transferred to military concentration camps.

The murder continues

Many of those involved in the program also took an active part in the Holocaust. Some of them were engaged in the development of the gas chambers in Bełżec, Treblinka and Sobibór extermination camps as part of Aktion Reinhard. Besides Auschwitz-Birkenau, Majdanek and Chełmno, these were the main sites of the murder of millions of people.
Result

By the end of 1941, every third resident of a mental institution in Germany was already dead, either from murder or from starvation, resulting in 93.000 beds available. An estimated 200.000 people died under the program. Hitler's grandniece, Aloisia Veit, was also among the victims. This program did not end in 1941. Doctors and nurses continued to perform in hospitals in Germany, Austria and Poland. The murders were carried out in such a way that the mistrust of the German population was minimized. Such precautions were not taken when people from the occupied territories were murdered. Brutal and violent action has been reported and recorded.

After the war

Doctors and nurses involved in the euthanasia program were by no means always brought to justice. Long after the founding of the new German states in 1949, senior officials escaped prosecution and continued to work in the German healthcare system. On 8 July 2013, the Federal Minister of Culture laid the foundation stone for a monument to the victims of this project in Tiergartenstraße, where the office of the service stood.