Children with disabilities were killed during the Nazi era, often by nurses. Some nurses killed children, saying that they were under orders. Propaganda about the need for “racial purity” was all pervasive and influenced much of the population, including nurses. The German people accepted the “mercy” killing of children with disabilities. We describe the children's “euthanasia” program, explore the influence of propaganda, ask why it was acceptable to kill children, and provide historical context demonstrating “slippery slopes” which can lead to abrogation of ethical principles. Discussion of such history is essential as the ethical principles which were breached are still the cornerstone of nursing practice today. Only by openly discussing past wrongs can we attempt to ensure that they do not happen again. Archival documents from Germany and Israel, including trial depositions and transcripts, provided material, supplemented by secondary classic sources.