Sir, We Hit Nuclear Missile Submarine: How 2 NATO Ballistic Missile Subs Collided

What You Need to Know: In 2009, a potentially catastrophic incident occurred when the United Kingdom's HMS Vanguard and France's Le Triomphant, both nuclear-armed ballistic missile submarines, collided deep beneath the Atlantic Ocean.

-Initially kept under wraps, the collision happened during routine patrols and was downplayed by both nations. HMS Vanguard sustained visible damage to its starboard side and missile compartment, while Le Triomphant's sonar dome and conning tower were affected.