I think it's too early to decide the cause of the crash. There was a story today in which another pilot is quoted as reporting a bright flash of light for a short period of time near the crash area. Obviously, the aircraft came apart rather quickly, so fast that the crew did not have time to radio in an emergency call. There was a report of a bomb threat a few days before the crash. One can only hope that the black boxes are found, which would allow determination of a probable cause of the breakup. As things now stand, all is speculation.

E. Swanson