the plane to crash it? experts are divided on this issue but hijackers usually have clear demands. that never materialized. and no terrorist group claimed responsibility which led investigators to believe the options are not available. the plane landed somewhere. as the months tick by and no pieces of the plane were discovered, some speculators whether it was possible the plane had landed. but no communications from the people on board or hijack demands made that less possible. mechanical failure. a theory that a catastrophic electrical or mechanical failure brought the aircraft down is still being considered. rapid decompression. the plane suddenly loses cabin pressure and the passengers and crew become unconscious. the plane on auto pilot flies until it runs out of fuel and crashes. without more evidence, they are all just theories, leaving