A German Submarine was sunk due to malfunction of the toilet !!

Submarines are widely used by most of the countries in their defense sector. Almost all the powerful countries have Submarines in their Navies.

A submarine is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability.  This term Submarine most commonly refers to a large, crewed vessel. For reasons of naval tradition, submarines are usually referred to as "boats" rather than as "ships", regardless of their size.
During World War II, Germany used submarines to devastating effect in the Battle of the Atlantic, where it attempted to cut Britain's supply routes by sinking more merchant ships than Britain could replace. (Shipping was vital to supply Britain's population with food, industry with raw material, and armed forces with fuel and armaments.) While U-boats destroyed a significant number of ships, the strategy ultimately failed.
In the World War II, One of the German submarine U-1206 had sunk due to malfunction of the toilet.
Funny to hear but the incident caused a life a soldier and kept 50 other people in front of death. All the persons on boarded were the soldiers in Navy and knew swimming. It would not be a Problem to swim offshore. But something happened beyond that, where they could not escape from the fate.
On 28 March 1945 the submarine departed from Kiel for its first training patrol in the North Sea, returning on March 30. The submarine departed from Herten Naval Base for a one-day patrol on 2 April, and its first active patrol began on 6 April when it departed from Kristiansand.

On 14 April 1945, 24 days before the end of World War II, while U-1206 was cruising at a depth of 200 feet , 8 nautical miles off Peter head, Scotland, misuse of the new toilet caused large amounts of water to flood the boat. According to the Commander's official report, while in the engine room helping to repair one of the diesel engines, he was informed that a malfunction involving the toilet caused a leak in the forward section. The leak flooded the submarine's batteries (located beneath the toilet) causing them to release chlorine gas, leaving him with no alternative but to surface. Once surfaced, U-1206 was discovered and bombed by British patrols, forcing Schlitt to scuttle the submarine. One man died in the attack, three men drowned in the heavy seas after abandoning the vessel and 46 were captured.

The remains of U-1206 were found at approximately 70 m (230 ft.) of water. The site survey performed by RCAHMS suggests that the leak that forced U-1206 to surface may have occurred after running into a pre-existing wreck located at the same site.

Source