Before Malaysia Airlines flight 370 disappeared from radar six days ago, there was no call for help.
Since it vanished, not a single piece of wreckage has been discovered.
These two facts are among the most significant in beginning to understand why there are so many theories being discussed on the missing plane's fate.
Neither government nor aviation officials have publicly focused in on any one possibility in explaining what happened to flight 370. But here are some of the more commonly circulated theories, with links for more information on each.
Let us know in the comments which you think is most plausible and your thoughts on what caused the Malaysia Airlines flight to disappear.
1. The plane was intentionally flown off-course and could have landed somewhere.
2. The flight was hijacked and flown to an unknown destination.
3. There was a complete and sudden electrical failure, disabling the plane's systems, including its transponder.
(Suggestions that the plane flew for several hours after its final transmission were bolstered Thursday with evidence supporting that "pings" of engine data continued for at least four hours after it disappeared from radar.)
4. A sudden, catastrophic explosion occurred, whether intentional (i,e. terrorism) or accidental (i.e. extreme cabin decompression).
5. Was one of the pilots conducting a dangerous and elaborate insurance scam? Malaysian officials hadn't ruled it out as of Thursday.
6. The pilot intentionally crashed the plane. However, there is little evidence to support that either of the pilots were suicidal.
7. And, of course, aliens. With experts baffled and no trace of the plane anywhere, if there was ever a time for your crazy uncle's supernatural conspiracy theories, this is it.
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