On this day, Ernst Thalmann died in the Buchenwald concentration camp
Many of the first victims of the concentration camps, before the Jews were sent to them, were communists and socialists. Thalmann was first arrested in 3 March 1933, this was after he went underground to avoid Nazi persecution after the Reichstag Fire False Flag. The reason of his capture are known, his location was given up to the Gestapo by Hermann Hilliges who lived next to the (not-so) safehouse.
Thalmann spent 11 years in solitary confinement, but he did manage to smuggle various notes and letters out. Members of the KPD who had fled to Moscow managd to convince the USSR to support Thalmanns release, however after the Molotov-Ribbentrop pact the Soviets massively cut back on their support for his release, including replacing the slogan of International Youth Day from "Long live Comrade Thälmann!" to "Long live the wise foreign policy of the Soviet Union, guided by Comrade Stalin's instructions."