I hope the Russian mini-sub that is currently being rescued has a happy ending. The National Geographic has a page on sub disasters. It illustrates just how dangerous the submariner's job is. As John Pike says, "Spaceships and subs have one thing in common: Either everything's working OK, or everyone's dead, and there's not that much in between".
Greatest Submarine Rescue in History. On 23 May 1939, the submarine Squalus sank in 243 feet of water off Portsmouth, NH when the engine room flooded due to a catastrophic valve failure. 26 men in the after part of the ship were drowned. Thirty-three others, including the commanding officer, LT Oliver F. Naquin, who were in the forward section, were trapped with no way to escape. Thus began the greatest submarine rescue of all time. Also, here's a short story about one of the survivors, Warren Smith.