Hartheim Euthanasia Centre The Hartheim Euthanasia Centre ( ) was a Nazi killing centre that was part of their euthanasia programme , since also referred to as Action T4 . It was housed in Hartheim Castle in the municipality of Alkoven near Linz in Austria . Hartheim Statistics . In June 1945 , during investigations by US Forces into the former gassing facility at Hartheim , American investigating officer Charles Dameron broke open a steel safe in which the so - called " Hartheim Statistics " were found . This was a 39 - page brochure produced for the internal purposes of the Nazi Euthanasia Programme ( " Aktion T4 " ) containing monthly statistics of the gassing of mentally and physically handicapped patients ( described in the document as " disinfection " ) carried out in the six euthanasia institutes on the territory of the Reich . In 1968 and 1970 an ex - employee of the establishment revealed , as a witness , that he had to compile the material at the end of 1942 . The Hartheim Statistics included a page on which it was calculated that in " disinfecting 70 , 273 people with a life expectation of 10 years " food to the value of 141 , 775 , 573 . 80 Reichsmarks had been saved . Numbers killed in the first extermination phase in Hartheim . According to these statistics a total of 18 , 269 people were killed in the gas chamber at the Hartheim Euthanasia Centre over a period of 16 months between May 1940 and 1 September 1941 , as follows : These statistics only cover the first extermination phase of the Nazi ' s euthanasia programme , sometimes called " Action T4 " , which was brought to an end by Hitler ' s order dated 24 August 1941 following protests by the Roman Catholic Church . In all it is estimated that a total of 30 , 000 people were murdered at Hartheim . Amongst the killed were the sick and the handicapped as well a prisoners from concentration camps . The killings were carried out using carbon monoxide poisoning . 14 f 13 " Special Treatment " programme . Just three days after the formal end of Action T4 a lorry arrived in Hartheim with 70 Jewish inmates from Mauthausen concentration camp who were subsequently executed there . The Hartheim killing centre achieved a special notoriety , not just because it was here where the largest number of patients were gassed , but as part of Action 14f13 Hartheim was also the institute in which the most concentration camp prisoners were murdered . Their number are estimated at 12 , 000 . Those no longer capable of working at Mauthausen , especially in the quarries , as well as politically undesirable prisoners , were brought to Hartheim to be executed . In the papers these transfers were disguised with terms like " recreation holiday " . The entries under " sickness " included " German haters " , " communist " or " Poland fanatic " . From 1944 the prisoners were no longer selected by T4 doctors ; it was only a question of securing space in Mauthausen camp quickly . Other transports came from the concentration camp of Gusen and possibly also from Ravensbrück . Death doctors . The Action T4 organisers , Viktor Brack and Karl Brandt , ordered that the execution of the sick had to be carried out by medical doctors because Hitler ' s authorisation ( dated 1 September 1939 ) only referred to doctors . The operation of the gas tap was thus the task of the gassing doctors in the death institutes . However , during the course of the euthanasia programme , the gas cocks were occasionally operated by others in the absence of the doctors or for other special reasons . Also , many doctors did not use their real names in the documents , but used other names to disguise themselves . The following death doctors worked in Hartheim : Niedernhart holding station . The Action T4 euthanasia centres had intermediate holding stations for victims . For example , many lorries carrying victims to their destination at Hartheim went via the Niedernhart Mental Institute in Linz , where Rudolf Lonauer was the senior doctor as he was in Hartheim . There victims were mainly killed by starvation or medical overdose . Time and again the screening and categorisation of prisoners was carried out . A bus was then filled with the chosen victims and driven to Hartheim . Move of euthanasia head office to Hartheim and Weißenbach am Attersee . In August 1943 a result of the air war the head office for the Nazi Euthanasia Programme was moved from " Tiergartenstraße " 4 in Berlin to the Ostmark region , which was then humorously described as the air raid shelt of the Reich . The statistic and documents by Paul Nitsche – correspondence , notices and reports ended up in Hartheim ( office department , accounts office ) and the Schoberstein Recreation Centre near Weißenbach am Attersee ( medical department ) – presumably as part of the move of the T4 head office . Victims . The clergy . A total of 310 Polish , seven German , six Czech , four Luxemburg , three Dutch and two Belgian priests were murdered . Many of them were transported from the Priest ' s Block in Dachau concentration camp . The chaplain , Hermann Scheipers , was also moved to the Invalid ' s Block , in order to be taken to Hartheim . Scheiper ' s sister – who stayed in contact by letter – tracked down a certain Dr . Bernsdorf , employee of the RSHA Berlin - Oranienburg , who was responsible for the clergy imprisoned in the Priest ' s Block . She confronted him with by stating that , in Münsterland , it was an open secret that imprisoned priests were sent to the gas chamber . Bernsdorf apparently became very nervous during the discussion and telephoned the Commandant ' s Office at Dachau . Scheipers reported that it was on that same day , the 13 August 1942 , that there was a response : he and three other German clergymen were moved from the Invalid ' s Block ( here the SS assembled prisoners for onward transportation ) back to the Priest ' s Block . Hartheim T4 staff . Those chiefly responsible for recruiting the lower - ranking staff , according to subsequent witness statements , were the two Gau inspectors , Stefan Schachermayr ( 1912 – 2008 ) and Franz Peterseil ( 1907 – 1991 ) , as well as Adolf Gustav Kaufmann ( 1902 – 1974 ) , head of the inspection department of the T4 central office in Berlin . " Other literature see main article : " Nazi Euthanasia Programme or Action T4