Benedikt Kautsky, an Austrian Jew and prominent Socialist, spent most of the Third Reich in concentration camps. In his 1946 memoirs, he described the great difficulty of mutual assistance among prisoners.
Everybody who was old, weak, or sick was condemned to death. There was little possibility of helping anyone. If I give something to someone I will be taking it away from somebody else. If I give something to someone who’s weak then I’ll keep him alive for longer, but in the end I won’t be able to save him. At the same time, I will be taking it away from a strong person and in doing so will be weakening him, so that he too will become weak and sick. The upshot is that I shall be harming both of them.
Source: B. Kautsky, Teufel und Verdammte (Zurich, 1946), p. 165
Translation: Lesley Sharpe and Jeremy Noakes