The US Navy, meanwhile, has employed the SUBSAFE system to reduce accidents on its nuclear submarines. The system was first implemented following the loss of the USS Thresher in 1963, which flooded due to a poor joint in its pumping system, resulting in the deaths of 112 Navy personnel and 17 civilians.29 SUBSAFE specifically instructs officers to experience “chronic uneasiness,” summarized in the saying “trust, but verify,” and in more than five decades since, they haven’t lost a single submarine using the system.30
