Testimony of SS Scharführer Erich Fuchs, in the Sobibor-Bolender trial, Dusseldorf (Quoted in BELZEC, SOBIBOR, TREBLINKA - the Operation Reinhard Death Camps. Indiana University Press - Yitzhak Arad, 1987, p. 31-32):
....We unloaded the motor. It was a heavy Russian benzine engine, at least 200 horsepower. we installed the engine on a concrete foundation and set up the connection between the exhaust and the tube.
I then tested the motor. It did not work. I was able to repair the ignition and the valves, and the motor finally started running. The chemist, who I knew from Belzec, entered the gas chamber with measuring instruments to test the concentration of the gas.
Following this, a gassing experiment was carried out. If my memory serves me right, about thirty to forty women were gassed in one gas chamber. The Jewish women were forced to undress in an open place close to the gas chamber, and were driven into the gas chamber by the above mentioned SS members and the Ukrainian auxiliaries. when the women were shut up in the gas chamber I and Bolender set the motor in motion. The motor functioned first in neutral. Both of us stood by the motor and switched from "Neutral" (Freiauspuff) to "Cell" (Zelle), so that the gas was conveyed to the chamber. At the suggestion of the chemist, I fixed the motor on a definite speed so that it was unnecessary henceforth to press on the gas. About ten minutes later the thirty to forty women were dead.
From the testimony of SS-Unterscharfuehrer Wilhelm Bahr in his trial at Hamburg (Quoted in Truth Prevails. ISBN 1-879437-00-7, p. 99):
Q: Is it correct that you have gassed 200 Russian POW's with Zyklon-B?
A: Yes, on orders.
Q: Where did you do that?
A: In Neuengamme [concentration camp].
Q: On whose order?
A: The local doctor, Dr. Von Bergmann.
Q: With what gas?
A: With Prussic acid [another name for Zyklon-B].
Q: How long did the Russians take to die?
A: I do not know. I only obeyed orders.
Q: How long did it take to gas the Russians?
A: I returned after two hours and they were all dead.
Q: For what purpose did you go away?
A: That was during lunch hour.
Q: You left for your lunch and came back afterwards?
Q: Were they dead when you came back?
Q: Did you look at their bodies?
A: Yes, because I had to load them.
Q: Why did you apply the gas to the Russians?
A: I only had orders to pour in the gas and I do not know anything about it.
SS-Doctor Kremer at a hearing on July 18, 1947 (Quoted in The Good Old Days - E. Klee, W. Dressen, V. Riess, The Free Press, NY, 1988, p. 258):
I remember I once took part in the gassing of one of these groups of women [from the women's camp in Auschwitz]. I cannot say how big the group was. when I got close to the bunker I saw them sitting on the ground. They were still clothed. As they were wearing worn-out camp clothing they were not left in the undressing hut but made to undress in the open air. I concluded from the behavior of these women that they had no doubt what fate awaited them, as they begged and sobbed to the SS men to spare them their lives. However, they were herded into the gas chambers and gassed. As an anatomist I have seen a lot of terrible things: I had had a lot of experience with dead bodies, and yet what I saw that day was like nothing I had ever seen before. Still completely shocked by what I had seen I wrote on my diary on 5 September 1942: "The most dreadful of horrors. Hauptscharf¨hrer Thilo was right when he said to me today that this is the 'anus mundi', the anal orifice of the world". I used this image because I could not imagine anything more disgusting and horrific.
Testimony of Magnus Wochner, SS guard at the Natzweiler Concentration Camp (Quoted in The Natzweiler Trial. Edited by Anthony M. Webb, p. 89):
... I recall particularly one mass execution when about 90 prisoners (60 men and 30 women), all Jews, were killed by gassing. This took place, as far as I can remember, in spring 1944. In this case the corpses were sent to Professor Hirt of the department of Anatomy in Strasbourg.
Testimony of SS Oberscharführer Erich Bauer (Quoted in BELZEC, SOBIBOR, TREBLINKA - the Operation Reinhard Death Camps. Indiana University Press - Yitzhak Arad, 1987, p. 77):
Usually the undressing went smoothly. Subsequently, the Jews were taken through the "tube" to Camp III - the real extermination camp. The transfer through the "tube" proceeded as follows: one SS man was in the lead and five or six Ukrainian auxiliaries were at the back hastening the Jews along. The women were taken through a barracks where their hair was cut off. In Camp III the Jews were received by an SS man... As I already mentioned, the motor was then switched on by Gotringer and one of the auxiliaries whose name I don't remember. Then the gassed Jews were taken out.