[Steely Tom]

I remember Thresher very clearly. It haunted me (as a third grader). I was interested in submarines and submarine warfare, having read several books on the subject by Robb White (obtained from the Scholastic Book Service, back when they published patriotic books).

I believe the Navy traced the problem to one or more bad silver-soldered joints in some seawater pipes; their thinking is that these had been weakened as a result of shock testing that had been done on Thresher shortly before her destruction with all hands.

I vividly remember the undersea image of one single plastic boot cover, which was - at the time - the only item from the boat that the Navy was able to find. Or so they said.

[Pan_Yan]

Seawater leak caused a reactor scram. Condensation in the high pressure air froze the air lines preventing an emergency blow. At least that was the best guess. Lots of procedures changed after that incident.