Heinrich Flach, born in 1899 in Berghofen (now Dortmund) and a father of two daughters, was arrested on 4 March 1938 by the Gestapo because of his activities on behalf of the KPD – the German Communist Party – and taken to Steinwache police station. The reason given for his arrest was “preparation of acts of treason”.

In the following weeks, Heinrich Flach was subjected to severe torture at Steinwache. After the last interrogation on 2 April, he left the room on the excuse of needing a drink of water, and threw himself into the stairwell of Steinwache. He died of the injuries sustained in the fall.