ocean. >> you can see everything and nothing. there's no sign of flight 370. >> how could an airliner with 239 people aboar just vanish? >> planes don't disappear. this is not a science fiction movie where all of a sudden it's there and it's gone. >> we have never seen anything like this. >> no, this is unpress debited. unprecedented. >> it's the longest a commercial plane has been missing in the history of aviation. >> we don't know. >> so many theories, so few answers. >> the evidence right now leads us to believe it's an intentional act. the question is by who. >> could satellite images provide key clues? >> it must be stressed that these sightings, while credible are still to be confirmed. >> as the families of passengers endure overwhelming anguish and uncertainty.