Nothing happened to the fish or corals. Another incident I had in a larger system was when a broken glass heater kicked on. I was sitting about 15 feet away from the sump the heater was in and all of the sudden what seemed to be like underwater arc welding happened. It went on for about 5-10 seconds before I yanked the plug out. The GFI never tripped, nor did the breaker. The fish were fine, but all of the xenia turned as white as copy paper. Very strange that they immediately lost all their zooxanthellae. If i remember correctly, a few other pieces browned out, but everything recovered.