Couldn’t have been a pleasant death.
I read that the engine and fuel were new and untested.
The old engine used rubber as a primary ingredient and it emitted a lot of black smoke and soot.
Prediction: the new fuel mix was probably created to be more earth friendly but obviously was unstable or needed more testing. I would bet this happened in part because of environmental BS.
Ironically, it may have indeed been a pleasant death, if you count unconsciousness. The explosive blast that broke up the ship could easily have caused unconsciousness. And if that wasn't enough, the wind blast and lack of oxygen at that altitude would also create unconsciousness.
Strange that they weren't wearing pressure suits - if they had to use parachutes, the suits would have saved them from serious injury or death. Maybe that's why the survivor is so badly hurt.