What should be learnt from these airplane disappearances is that the current way for tracking airplanes is ineffective...
Think about it, you can find your stolen phone but not a huge airliner...
My thoughts are with the families of the passengers and crew that were onboard the stricken jet.
We can't say what might have been the cause of the crash because there isn't any evidence yet. The black box would be of great help.
For those of you who aviation isn't their strong hold, the plane has 2 black boxes (actually they are orange), 1 records the voice in the cockpit and the other records airplane parameters. If the pilots were discussing the problem amongst themselves, as they likely were the investigators can establish if pilot error is in question. The other black box records engine data, autopilot data, position of the flight controls etc. this might point to some machanical failure. This recorder also has wind speed outside the plane. With these 2 black boxes the investigators can start to understand what the plane experienced and the crews' reaction. It is known till now that the pilot asked the controller to climb to a higher altitude due to the storm, the controller didn't give permission for the pilot to climb ( in busy airspace it's common that pilots have to wait until the attitude they requested is clear of traffic). One insteresting thing to note is that all pilots are taught "U can never out climb a storm" ( it grows with such a rate that an airliner rate of climb isn't enough to fly above it, besides these storms may go up to 40,000 feet).
I hope that was of some help to understand the current situation and avoid being mislead by unreliable media sources.