Naval attack in Korea

And while that is almost a "dog bites man" story at this point, this one is more serious. A South Korean navy ship is sinking due to a torpedo attack. Apparently there was a fire-fight in South Korean waters with an unidentified North Korean ship, and then the torpedo.

The only significant difference between this and previous incidents is the damage to the South Korean vessel. I have no illusions--both sides will keep this contained, and the undeclared naval skirmishes will continue. I'm curious, though, as to whether it was a lucky hit, or if the DPRK navy is actually getting better.