Whats the elevation? The PC12 glides quite well. From 11,000ft you would have a very decent glide range so they should have had more than enough time to get out a mayday call.
If there is a relatively small debris field then that usually means that it came down rather vertically, and with the plane basically being intact, that would imply a slow rate of decent.
One could quite safely assume a glide.
Dust storm in the area? Engine failure/Flame out due to ingestion with also the antenna's being destroyed/disabled by the sand/dust hitting it.
One would have to ask why then, that you would push into that? Due to the critical patient on board?
How far along its flight path was it? Is fuel exhaustion due to stronger than forecast winds a possibility?
Again though, was the critical patient a factor in deciding to push on, hoping that you could make it?
These are all questions that the investigators will be asking. The report should be out soon enough.
RIP all involved.