Steve, my biggest fear was what you had predicted was the achilles heel of your tank (the closed loop in the base of the tank). I was really expecting you to say one of the PVC fittings gave way and drained the tank.
I can't fathom how you must have felt pulling out those enormous corals that had died. I would not have been able to post what you did, with a list of positive thoughts. Your tank is world-famous.
This is a sad day.