They all got out alive. Top marks to the Captain. End of story. If I ever meet him I will buy him a very large beer.
Speculate all you like. What actually caused the crash? Choose from:
Double engine failure.
Icing leading to double flameout.
Icing leading to compressor stall.
Pilot shut down both engines by mistake.
Pilot ran out of fuel.
Severe airframe icing leading to massive increase in drag.
Ditto leading to massive loss of lift.
Fuel contaminated.
Fuel filters frozen with water caused by internal condensation.
I could go on with another couple of dozen wild guesses - why don't we just wait for the inquiry to tell us the true cause?