No, not going tin foil..But does anyone re-call the story a few years back about a U.S. Sub and a Russian sub colliding?
The writer of this story, Christopher Drew, along with Sherry Sontag, wrote Blind Man's Bluff. It's worth reading, and no tin-foil hats are needed. Those Cold-War warriors pulled some pretty amazing feats of underwater espionage.
Nevertheless, this kind damage wasn't caused by anything sinkable. Besides, the San Francisco undoubtedly brought back samples of whatever they hit. The Navy knows exactly what it was. We're free to guess, but my money is on an uncharted undersea mountain, hit during a high-speed deep transit.
That was the Kursk. The Russkis claim we rammed their sub but as it turned out it was a faulty missile that blew it up.