The Navy builds them strong...
 My understanding is the USS San Francisco is a "fast attack" (hunter-killer)  submarine. She went aground on an uncharted sea mount earlier this month,
about 300-miles southwest of Guam. My further understanding is that she was
almost at flank, or top speed (which is classified), and went to almost zero immediately upon impact. One crewmember died, and a number of others were injured.

Well, a look at this photo shows that the Navy builds 'em strong. This damage
may look bad, but if that submarine had been built to anything less than the
specifications the Navy requires, she wouldn't have come back at all.

The sonar dome is gone - it is made out of 2" thick fiberglass. The hull appears to be some what crumpled also.