At each bunk level, six to eight people slept. The center brick and mortar duct was used for heating. "If the barrack walls were suddenly to fall away, many thousands of people, packed together, squeezed tightly in their bunks, would remain suspended in mid-air. Such a sight would be more gruesome than the medieval painting of the Last Judgment..." Tadeusz Borowski in the book "This Way for the Gas, Ladies and Gentlemen."