The government got Hughes to build the Glomar Explorer under the guise of undersea mining (fact). They grabbed the entire sub and started the lift. According to what I've seen on the tube they got the sub 1/3 +/- up and the forward section of the grab assembly broke. The aft 1/3 was salvaged, seamen were buried at sea, and ...! The Glomar Explorer is fact (Hughes Tool could do anything), the rest...???
I remember that they got part of it up and when the section broke off they thought they were goners; they expected a nuclear detonation. IIRC, they actually brought back part of the sub and it was all very hush, hush and everything just kind of "disappeared", according to this special I saw.