Transponders/Flarm on fixed structures?
Really?
This was a tragic accident, the reasons for which may or may not be horribly straightforward. But if even we, in the industry, cannot keep a sense of proportion (as seen in some entries in this thread), then it's little surprise if those with an agenda make headway.
I have to say that rather than "something must be done", my reaction to this unhappy event is that despite it being rush-hour, close to the centre of one of the most populated cities in the Western world, the really rather low resultant casualties and disruption suggest that the regulators and responders probably have it about right. Chance played a part, of course, but that can work both ways.
And before anyone starts, no - I am not making light of the tragedies for the families of Capt Barnes, Mr Wood, the critically injured person and the other casualties. Far from it.