In 1945, the German submarine "U-1206" was sunk after a toilet malfunctioned, resulting in seawater flooding into the hull, which when coming into contact with a battery, created chlorine gas, forcing the submarine to resurface. At the surface, it was discovered and sunk by Allied Forces. This case may not be due to toilet malfunction, but due to the possibility that the pressurized flushing system in the U-Boats, which was extremely complex and required a training course to operate, may not have been properly operated.