Looks like sea wanted to enter my fort badly.
After some fights with goblins I had to build a hospital. Standard thing. But it needed a clear water. So decided to build a water tank under it, like I always do. Dug out some tunnels and channeled chimney down, used standard doors to seal walkways from water tunnels, like I always do, elsewhere floodgates. Everything prepared, tank constructed, pump for clearing water made, all that was left was to mine out 2 last squares standing in the way for me to make my standard water tank.
I carefully planned tasks so both squares would be mined out at the same time, and both miners would just run away, like always.
But it wasn't like always. Before today I haven't tried to mine into the sea. And sea's a harsh lover. As first miner dug into the sea whole water went bursting through and filled aqueduct in an instant. I was like "hell, I can live without those two miners". And then I saw the bigger picture.
My safety doors didn't stop the water flow, and my fort was instantly filled with 7/7 water, except top floor. Last hope were caverns underneath my fortress, hoing they would take all the water. But for my luck I had sealed access to them, to not let any FUN out of them.
So, apart from now-ended siege outside, probably a vampire or two in my fort I have a loads of water with no means to dispose it somewhere.
Good thing I recorded the whole mess I made, for those interested:
http://www.twitch.tv/thatplayingdude/c/3014348And that song at 3:00 mark just made everything worse.