Forty minutes after take-off, a four-minute-long series of automatic radio messages began transmission. The problems and warnings transmitted to Air Traffic Control were all automated messages; there was no direct human contact. The Airbus is a fly by wire plane, in other words, when there is a crucial event, the system defaults to automated control.
Currently what happened on that flight is under conjecture. Theories range from bad weather, lightning, failure of pitot (speed sensors), to the ruptured tail rudder.
Over 400 pieces of the wreckage have been found. Only a small percentage of the mortal remains of the passengers have been recovered.