Engine failure? All the parts looked to be right next to the aircraft cabin and fuselage?
Main Rotor blades did not seem to show much rotational damage on the leading edges.
Same for the Tail Rotor Blades from what is visible.
It was windy....but they were landing at the airport....not some confined area.
Christmas Valley is pretty much out in an open Plain....no mountains very close as I recall.
News reports are saying the landed hard then rolled over.
Seems some folks are being pretty tight lipped.....even the pprune Accident Investigation Crowd.