The USS Thresher was the first ever U.S. submarine to sink to the seafloor. It’s hypothesized by some military experts that the infamous John Walker who was acting as a mole within the U.S. Navy, tipped off the Russians as to the location of the USS Thresher and that the submarine was attacked in revenge for a Soviet submarine entitled “K-129” which was lost 10 weeks prior to the USS Thresher event. The Russians believed that a U.S. Navy Destroyer ship ran over and through the Russian submarine K-129 despite the U.S. Navy claiming no involvement whatsoever. The forensic evidence points towards implosion due to a leak of some kind, most likely near the seals of the propeller or the trash shoot, making it impossible for the USS Thresher to rise to the surface or be saved by a nearby vessel