Don't bunch microlights and autogyros, very different beasts with significantly different accident records.
Aircrew fatal accident rates in the UK (1990-1999, from CAP701) are:-
Commercial transport light aeroplanes- 1 per 400,000 flights.
Other light aeroplanes - 1 per 71,500 hrs
Public transport helicopters - 1 fatal accident per million flights.
Other helicopter flights - 1 fatal per 53,000 hrs
Microlights - 1 fatal per 50,000 hrs
Gyroplanes - 1 fatal per 8,000 hrs
My own sympathies to those who survived in the helicopter, and the friends and relatives of those who didn't survive in the microlight.
It's a difficult, high workload, crowded bit of airspace - I don't recall ever flying in that immediate vicinity without some need to take avoiding action. But, that makes the accident no less tragic, nor the lessons that we'll be asked to learn from it any less important.
G