Navy officials say they so far ca n't pinpoint the cause . Divers are scouring the submarine for the 13 remaining sailors . Officials warn there is no hope of finding any survivors . The search area has been expanded to include a wider swath of ocean than previously thought, and officials say they expect it will take several days before all possible debris from the plane can be recovered.
Divers are scouring the submarine for the 13 remaining sailors . Officials warn there is no hope of finding any survivors . The search area has been expanded to include a wider swath of ocean than previously thought, and officials say they expect it will take several days before all possible debris from the plane can be recovered.