The USS Thresher was a nuclear-powered attack submarine and the lead ship of her class in the United States Navy. On the fateful day of April 10, 1963, the vessel was participating in deep-diving tests and was conducting routine operations approximately 220 miles east of Cape Cod. Convoyed by the surface ship USS Skylark, Thresher established communication with her support vessels before submerging. During the tests, she was reported to have encountered significant problems shortly after diving. The last communication received from the submarine was a mere moment before the connection was lost, failing to confirm the situation onboard.

The subsequent search and recovery efforts revealed that the submarine had gone down with all 129 crew members onboard. Investigations into the incident led to significant scrutiny of nuclear submarine operations and safety measures. The U.S. Navy initiated a thorough investigation, which ultimately suggested that a combination of mechanical failure and human error, coupled with inadequate design features, led to the disaster.

This tragic event prompted substantial changes in submarine design and safety protocols for the Navy. Increased emphasis on systems engineering, combined with enhanced crew training, aimed to prevent such occurrences in the future. The loss of the USS Thresher remains a crucial part of naval history, underscoring the complexities and risks associated with nuclear submarine operations.