During the Cuban Missile Crisis, the US Navy dropped a series of "signal" depth charges (the practice of depth charges the size of hand grenades) on a Soviet submarine (B-59) in the blockade line around Cuba. Unaware that the submarine was armed with a nuclear-tipped torpedo, the situation escalated. The submarine captain, Valentin Grigoryevich Savitsky, considered launching a nuclear torpedo, but the commander of the submarine flotilla, Vasily Arkhipov, objected, preventing the nuclear launch. This event was one of several after which a nuclear war almost started due to a misunderstanding.