South Korea once again finds itself in a dilemma as to what action to take after yet another attack that almost certainly came from North Korea. As expected, a joint investigation team tentatively concluded on April 25 in the postmortem on the sinking of the South Korean Navy patrol boat Cheonan that "the shape of the fracture lines and conditions of the interior and exterior of the hull indicate an underwater explosion," adding that "we believe that it was a close-range explosion rather than a direct hit as the interior and exterior of the hull had no traces of burns or melting due to heat or a puncture."