Carl, maybe there is a relation between the London and NY blackouts.
it was also noted elsewhere (prudentbear.com) that both took place 10 minutes after market close (local time) on a thursday. oddly, i can't verify this since none of the stories i read about this blackout mention the time. in fact, its actually pretty conspicuous by its absence. (every journalist know's to include the 5 w's, which includes "when".)