FTE Pruner
I'm amazed that so many here apparently take seriously the idea of a healthy landing followed by a crew-fatal 15ft roof collapse which was not even free-fall. Being underneath a collapsed roof and a helicopter: a grievous situation. Being inside an impact-engineered crew compartment which slumps through a partially-intact low flat roof: I just don't buy that as a prime candidate for what led to this terrible outcome for the crew.
Is there a structural engineer here with expertise regarding the degree to which a frangible surface such as an elderly pub roof may not do the catastrophic damage to an airframe that hitting rock, clay or concrete would, despite still causing crushing deformation and very significant Gs (as regards survivability)? There's a lot of room for catastrophe in the zone between controlled autorotation on the one hand and streamlined terminal velocity on the other.