Had a bout of what I think was RTN. Found my heater out and water temp about 10-15 celcius which probably shocked the hell out of the system. Looks like this coral was the only one affected, don't exactly know what kind it was, probably some kind of staghorn. Anyway, this is what was left of it.
Snapped off a couple of branches before I took the picture that hadn't been hit yet, what are the chances of them surviving?