It appears that the evidence shows without a doubt that North Korea sunk the South Korean navy ship. The north are throwing down the gauntlet for war if they are punished:
NKorea warns of war if punished for ship sinking - Yahoo! News
There were 46 South Koreans killed but it could get interesting for the 28,000 US troops stationed there.
NKorea warns of war if punished for ship sinking - Yahoo! News
There were 46 South Koreans killed but it could get interesting for the 28,000 US troops stationed there.