One thing does surprise me. Why did the flight deck all succumb when they would have had full harness and more warning of the pending accident than anybody else? The cockpit area seems relatively undamaged.
I would imagine it is because the cockpit area is at the end of the a large pivot/moment arm. i.e. if it hit tailfirst with the nose high then the rapid deceleration (short skid length) will have derotated the cockpit into the ground with enormous force. Evidently non-surviable force.
It will be interesting to see the distribution and seriousness of the injuries in the final report. Based on my theory (just that) the nearer the front the more likely you would have been to sustain serious injury.
A4