It usually gives you a warning when the site is about to go offline. Did it not show up?
live chess maintenance

I'm really sorry about that. There was an issue happening on live chess that i needed to get fixed asap before it affected too many peoples games and only a restart could do it.
Unfortunately in this instance, there really wasn't enough time to give anyone a warning although i would have liked too and preferred too. I had to call in one of the programmers to get this done.
I am really sorry it affected your games, i was hoping to keep this to a minimal affect as possible.
I was right in the middle of a game on live chess when suddenly, BAM, maintenance. It was on my time, so is this going to count as a loss or what?