It was organised by the Schutzstaffel - SS-Baubrigade I -- which was first under supervision of the Sachsenhausen concentration camp near Berlin ; and from mid-February 1943 under the Neuengamme camp in northern Germany . It was organised by the Schutzstaffel - SS-Baubrigade I -- which was first under supervision of the Sachsenhausen concentration camp ; and since mid-February 1943 ran under the Neuengamme camp in northern Germany .