Paul,
One thing that I am at odds to explain over this whole incident, is this:
Why, when the towers collapsed was there not a huge explosion and ignition of the tinder dry grass and trees around the Lines.
As far as I am aware, there was no such occurence.
And considering that the DC link only has fuses at the supplying end and the Inverter end(these are 100's of km's apart), what gives?.
With these sorts of voltages, you'd normally expect a disastrous blaze after an event like this!, but nothing.