Mystery deepens: If you were a missing Malaysia Airlines jetliner, where would you be? Ten days after Flight 370 disappeared with 239 people on board, authorities are still scratching their heads. Twenty-four nations are involved in a search that spans thousands of miles, extends over 11 countries and stretches as far north as Kazakhstan and south into the Indian Ocean. Investigators believe it was a deliberate effort, but beyond that plenty of mystery remains. Did one or both pilots intentionally take the plane? Maybe. Was it hijacked? Possibly. Were terrorists involved? Who knows? There are a lot of loose ends.