The USS Thresher (SSN-593) was a nuclear-powered attack submarine of the United States Navy, launched on July 9, 1960. It was designed for anti-submarine warfare and had advanced technology for its time, including a nuclear reactor that allowed for extended underwater operations. Tragically, the USS Thresher sank during a deep-diving test on April 10, 1963, off the coast of Massachusetts, resulting in the loss of all 129 crew members. The incident led to significant changes in submarine safety protocols and the establishment of the SUBSAFE program to enhance the safety of submarines in the fleet.