On 25 October 2003, USS Hartford, a United States Navy nuclear-powered Los Angeles-class submarine ran aground while leaving the harbor of the NATO Naval Base at the Santo Stefano island in La Maddalena archipelago, Sardinia. Approximately nine million dollars' worth of damage was done to the submarine, and it was out of service for seven months. An investigation into the accident revealed that basic navigational errors combined with equipment failures were to blame for the submarine running into the rocky shallows.