A U.S. Navy Attack Submarine Ran Aground (And Nearly Started a Nuclear Crisis)

What You Need to Know: In October 2003, the U.S. nuclear-powered submarine USS Hartford ran aground off Sardinia's northern coast, severely damaging its rudders, sonar, and electronic systems.

-Despite potential environmental risks, including the presence of a nuclear reactor and Tomahawk missiles possibly carrying nuclear warheads, the U.S. Navy kept the incident secret.

-Leaks from crew members' families brought the grounding to light. The vessel received emergency repairs before returning to Virginia for a full overhaul.