Růžičková was sent to Hamburg, which was being bombed regularly by the British and Americans. Under the auspices of the Neuengamme concentration camp, laborers were assigned to work in sub-camps in the area around Hamburg. Růžičková was put to work protecting and repairing an oil pipeline and maintaining gas tanks, which were subject to daily bombardment. She was able to remain with her mother, but suffered greatly from hunger and dangerous working conditions. However, she was able to earn some extra food from other prisoners by singing for them. In addition to working on the oil pipeline, she worked in the shipyards of Hamburg. In January 1945, Růžičková was moved to the Tiefstack sub-camp, where she worked in a cement factory. As Allied forces advanced, the prisoners were made to dig booby-traps for tanks.