The Theories
There are several theories on what caused the plane to disappear.
Accident
At first, it would seem likely that a large fire or a power outage could cause the plane to go down.
However, there are many reasons why an accident would be unlikely. These points been listed in The Disappearance
Hijacking
Further investagtions reveal that there were two men who borded the plane with stolen passports. Could they have been involved with the disappearance?
The two men identified as Pouria Nour Mohammad and Seyed Mohammad Reza Delavar were Iranian men that used stolen Austrian and Italian passports to board.
However, Malaysian authorities have said that these men are likely not terrorists but rather refugees.
Other Theories
There are many other theories on what happened to the plane, but there isn't enough information to make any of these probable.