Truly a sad thing, this. Glad the guy is okay. If you get Road & Track, this is (or was...) the Enzo they've used for their testing. Had an article on it in the last issue even, written by the driver/owner. He drove it as a daily driver, and had something like 30k miles on it.
It was a charity event, where they close down a stretch of road and the participants get "speeding tickets," the proceeds of which go to support charity. Run by the same chap that built the new track here, Larry Miller.