Ages ago I borrowed one of the books about it from the library, though only recently wondered how they got it out.

http://en.wikipedia.org/wiki/Russian_submarine_Kursk_(K-141)

Part 1
[video=youtube] https://www.youtube.com/watch?v=iTcogT-m2mk [/video]

Part 2
[video=youtube] https://www.youtube.com/watch?v=-tYY5nxovXE [/video]

And the latter half of this video has the potential cause theories
[video=youtube] https://www.youtube.com/watch?v=j0ZyuVDdM24 [/video]