The Pluton was a fast minelaying cruiser built for the French Navy in the late 1920s. She was also able to carry 1,000 troops on her mine deck as a fast troop transport. Shortly after completion she was modified and became a gunnery training ship, replacing the elderly armored cruiser Gueydon. Shortly before the beginning of World War II, she reverted to her original role and most of the gunnery training equipment was removed. She was sent to Casablanca, in French Morocco, when the war began to lay a minefield, but the order was cancelled a day later and she was ordered to disembark her naval mines. She exploded while landing her still-fuzed mines on 13 September 1939.