1942 January 14 Dr. Mennecke, a physician involved in the euthanasia program, writes in a letter: "The day before yesterday, a large contingent from our euthanasia program has moved under the leadership of Brack to the Eastern battle-zone... It consists of doctors, office personnel, and male and female nurses, from Hadamar and Sonnenstein, in all a group of 20-30 persons." (Science)