Gekrat

The Gemeinnützige Krankentransport GmbH  listen  (known as "Gekrat" or "GeKraT", commonly translated as "Charitable Ambulance") was a National Socialist subdivision of the Action T4 organization. The euphemistically named company transported sick and disabled people to the Nazi killing centers to be murdered under the Nazi eugenics program and was known for the gray buses it used.

Gekrat was created to transport the victims to the Nazi killing centers Grafeneck Castle, Brandenburg, Schloss Hartheim, Schloss Sonnenstein, Bernburg and Hadamar Euthanasia Centre. It also handled some administrative tasks. When family members wrote to hospitals where their loved ones had been sent, that mail was forwarded to Gekrat, which did not answer inquiries but allowed institutions to provide limited information in reply. The information was provided only as a means for the Nazis to continue receiving payment for room and board.Reinhold Vorberg headed the central office for transportation. Hermann Schwenninger was registered as the chief executive.

After 1941, Gekrat also handled transportation for the Action 14f13 program, which eliminated sick prisoners and those no longer able to work from Nazi concentration camps by bringing them to the killing centers, where they were sent to the gas chambers and killed.

...
Wikipedia