I've been flying for a few decades now. Part helicopter, part fixed wing. I have flown police helicopters, and have suffered a sudden engine failure in a low-ish hover, at night over a very major city centre.
The one thing that seems pretty obvious from today's pictures is that this wasn't a 'crash' per-se. As others have suggested it seems like a pretty superb attempt at a forced landing. The cause of the aircraft's rapid, and undoubtedly involuntary descent is likely to remain the subject of speculation for some time yet. But the fact remains, this aircraft was 'landed', albeit in the most difficult circumstances it is possible to imagine.
Every bone in my body strongly suggests that this pilot did the most fantastic job in those crucial seconds. Tragically, he and others were dreadfully, dreadfully unlucky.
Such a great shame. I'll offer a toast tonight.