The South Koreans are leaning toward an explanation:
"A torpedo or a sea mine might have been involved but a torpedo is a more realistic cause than a mine," [defense] minister Kim Tae-Young told parliament as divers resumed a search for 46 sailors missing from the 1,200-tonne corvette.
Sailors operating the ship's sonar detection system had not detected any approaching torpedo, Kim said, adding: "Patience is needed until investigation results come out."
A week after the disaster, officials are still groping for answers as to what caused the ship to break in two in the Yellow Sea on the night of March 26.
So we have two immediate questions. Did North Korea attack the ship? And just what does South Korea do in response to the murder of their sailors?
After that, the questions might come fast and furious.