exit malaysian air space, which is sort of the odd scenario and acars system. then the route is completely turned around dramatically. that suggests that either the pilot intentionally did it for whatever reason or that something was happening in the cockpit on the airplane with some possibly some of the passengers. we can't rule out the possibility of a passengers -- of a terrorist link to that. but one thing we do know for certain, the transponders turned off and acars routes changed. what caused that? we don't know at this point in time. it's either an accidental fire that may have caused that or a more deliberate intentional act. that's why we need to get to the bottom and get the black box in the indian ocean. >> alan, there's a good deal of speculation about what's called the pain stew ard scenario, that however this event started, that in the end, all of the people on the plane, including the pilots