The “euthanasia program” refers to the systematic murder of people with physical and mental disabilities by Nazi Germany, beginning in 1939. Known internally as “T4,” named after the coordinating office at Tiergartenstrasse 4 in Berlin, the program killed over 70,000 men, women, and children in its official phase alone, with thousands more dying in a decentralized continuation that lasted until the end of the war. It began roughly two years before the Nazi regime started systematically murdering Europe’s Jews, and it served as a testing ground for many of the methods later used in the Holocaust.
How the Program Started
In the autumn of 1939, Adolf Hitler signed a secret authorization granting certain physicians the power to give a “mercy death” to patients judged incurable. He deliberately backdated the document to September 1, 1939, the day Germany invaded Poland, to frame the killings as a wartime measure. The authorization was never a formal law. It was a private letter, designed to shield participating doctors, nurses, and administrators from criminal prosecution.
Hitler placed two men in charge: Philipp Bouhler, head of the Chancellery of the Führer, and Dr. Karl Brandt, his personal physician. Their task was to identify, select, and kill institutionalized patients across Germany. The entire operation was kept secret from the general public.
Who Was Targeted
The program initially targeted people deemed “incurable” based on questionnaires sent to psychiatric hospitals and care institutions across Germany. Doctors reviewed registration forms and made life-or-death decisions, often without ever examining the patient in person. The conditions that could mark someone for death included schizophrenia, epilepsy, dementia, physical deformities, and a range of other disabilities. Children were not spared. Infants and young children with disabilities were killed in designated “special children’s wards,” often by nurses who administered lethal doses of medication or simply starved them in unheated rooms.
By March 1941, Brandt and Bouhler expanded the criteria. It was no longer limited to those considered “mentally dead.” Any patient incapable of productive work could now be selected. Records from the program show that over 80% of those chosen were classified as unable to work. Labor ability, physical strength, and behavior all became factors in who lived and who died.
How the Killings Were Carried Out
In the earliest phase, victims were killed by lethal injection. The program then shifted to carbon monoxide gas, piped into chambers disguised as shower rooms inside six dedicated killing centers set up in converted psychiatric institutions. These facilities, including Hartheim, Bernburg, Pirna-Sonnenstein, and Hadamar, processed patients transported from hospitals across the country. Families received falsified death certificates listing invented causes of death.
The gas chamber method developed here was not incidental. It became the blueprint for the mass extermination camps of the Holocaust. Personnel who had operated the T4 killing centers later transferred directly to camps in occupied Poland, bringing their expertise with them.
The Children’s Program
The killing of children actually preceded the broader adult program. An estimated 5,000 children were murdered through starvation, exposure in unheated wards, or the administration of poisons. Nurses carried out many of these killings, some claiming they were simply following orders. Nazi propaganda about “racial purity” and the supposed burden of caring for disabled people had permeated German society deeply enough that the killing of disabled children was broadly accepted, or at least not widely resisted.
Public Protest and the Official Halt
Despite the secrecy, word spread. Families noticed that relatives in institutions were dying under suspicious circumstances, sometimes in clusters. One of the most forceful public challenges came from Clemens August von Galen, the Catholic Bishop of Münster. On August 3, 1941, he delivered a sermon directly accusing the government of murder. “Lists are being prepared of inmates who are classified as ‘unproductive members of the national community,’ who are to be removed from these establishments and shortly thereafter killed,” he told his congregation. He pointed out that Article 211 of the German Penal Code, which punished deliberate killing with death, was still technically the law.
Von Galen’s sermon, along with broader public unease, pressured Hitler to officially order the program’s suspension in August 1941. By that point, the centralized T4 operation had already killed over 70,000 people.
The Killings Continued
The official halt was largely a formality. Killings continued on a decentralized basis across hospitals and institutions throughout Germany and occupied territories, a phase historians call “wild euthanasia.” Instead of centralized gas chambers, staff at individual facilities killed patients through starvation, lethal medication, and deliberate neglect. This phase was harder to track and continued until the war ended in 1945, adding tens of thousands more victims to the total.
Simultaneously, a parallel program called “Special Treatment 14f13” extended the killing apparatus into concentration camps. Beginning in spring 1941, the SS and the Chancellery of the Führer agreed to murder concentration camp inmates deemed unfit to work. The operation was directed by Viktor Brack, who had already organized the T4 killings. T4 doctors traveled to concentration camps, reviewed registration forms, and selected prisoners for death. The victims were then transported to the same gas chambers used for disabled patients at facilities like Bernburg, Pirna-Sonnenstein, and Hartheim. A second wave of these killings began in April 1944, targeting weakened prisoners primarily from Mauthausen and Gusen.
The Program’s Role in the Holocaust
The euthanasia program was not a separate chapter from the Holocaust. It was its precursor. The T4 operation pioneered the use of gas chambers disguised as showers, developed the bureaucratic machinery of mass selection, and trained the personnel who would go on to run extermination camps. The same psychological mechanisms that allowed doctors to kill patients while still seeing themselves as healers, a phenomenon the psychiatrist Robert Jay Lifton called “doubling,” enabled medical professionals to participate in genocide on a much larger scale.
Karl Brandt, one of the program’s two leaders, later framed the killings as a medical burden on the doctors who carried them out, claiming physicians were the real victims. This inversion of responsibility was characteristic of the program’s entire moral architecture: a state-sponsored killing operation wrapped in the language of mercy, medicine, and public health.