Now that is a story!
Not a reef disaster but back when we had the Northridge earthquake in 1995, I had a 240G system with White tip reef sharks, a leapord shark and a very large 5' green morray eel.
The quake was a rolling one that cause the walls of the house to sway enough that they hit the pvc plumbing lines on the back on the tank. Those lines were about 4" away from the wall. The wall hit them so hard that they embedded themselves into the drywall breaking them and leaving a cut through the wall all the way up the wall where the pipes were behind the tank.
When the quake hit, my wall unit around my bed came tumbling down on me. I raced out of the room and ran or stumbled (in my birthday suit) down the stairs to the tank to find the water pouring out of it. As I reached under the tank to try to figure out where the water was coming from I got the shocks of my life as the water was pouring all over the power outlets and I standing on wet carpet.
In a panic but also a moment of clarity, I ran to the garage for a couple trash cans that I used to mix up water and siphoned enough water out of the tank to save the fish. I reached in and grabbed the sharks and the eel (by hand) and put them into the trash cans. My eel was used to being handled so that part wasn't a big deal and I was in such as state of shock that the thought of getting bit didn't even register. Fortunately the sharks and eel cooperated.
The end result was no fish lost. 200+ gallons of water on the floor to go along with an empty tank. The fix was easy enough once I pinpointed what broke and I had it back up and running a day or 2 later.
I will never forget that as long as I live.