This happy interim period ended for Steinbrück in April 1944, when another air raid destroyed the apartment that he and Cäcilie had been living in. Steinbrück improvised a shelter for Cäcilie and himself in the backyard of the destroyed apartment, building it with tools and supplies that he had taken from other ruined buildings. This would prove a watershed moment for Steinbrück. He had been living outside the law of the Nazi state for some time, but now he would begin to support himself by stealing.
Cologne in the late summer of 1944 was already a city in ruins. Most of its population had been evacuated as the Allies broke out from Normandy in August and rapidly drove for the German border. Cologne would become something of a supply depot for the German military as they organized their defense of the Reich’s western border. For Steinbrück this city full of supplies but devoid of people provided an incredible opportunity. He would connect with several other fugitive men, deserters and the like, and begin a spree of capers.
It all started innocently enough. At first, Steinbrück and his crew attempted to earn a living doing rebuilding work for other Germans who had remained in Cologne. They supplied this operation by first stealing tools, then by stealing cement, and finally by stealing an entire cement truck. Soon, though, they dropped the pretext of doing work entirely and began raiding the military supply dumps, stocking up on weapons. On the first day of September, they carried out their greatest heist, stealing 2,600 pounds of butter. It had a street value of 123,000 Reichsmarks, as much as a common laborer would make in two lifetimes.
Steinbrück’s career as a black marketer came to an end on September 29, 1944, when a military patrol discovered his hideout and weapons cache in the shelter behind the apartment on Schönstein Street. Steinbrück had been there when the patrol arrived but managed to escape out the back window. Cäcilie was not so lucky. The patrol detained her in the shelter, using her as bait in the hopes that some other members of the gang would return. They would not have to wait long.
By coincidence, the night before the raid on Schönstein Street another pair of German living outside the law in the rubble of Cologne, the deserter Roland Lorent and his sixteen-year-old sidekick Hans, had caused some trouble of their own. The two of them had organized the murder of a local Nazi Party boss. While Lorent and Steinbrück did not know each other, the Gestapo suspected that there was a connection between the murder and the hideout they had just discovered on Schönstein Street.