Most unfortunate. Coincidentally I just happen to have seen some video of this just the other day, a head on view of this incident. No doubt the pilot simply could not see the fence in his blind spot.
Also coincidentally -and also most unfortunately- I personally witnessed a very similar incident at Geneseo a few years ago, a triplane crashing literally right in front of me. As in this incident the pilot was o.k. and just a bit shaken up. Oddly and again coincidentally (LOL) I am reminded as today is my birthday (still the 13th here in the US) that on my 18th birthday in 1985 I was present at an airshow at Niagara Falls when the US Navy Blue Angels tragically crashed, again literally right in front of me. Nothing funny about that. I'll start another thread with my Dr1 crash pics and some others from Geneseo as well.
Best regards, Daniel.