Apparently, the server died, and the site was down for 10 hours.
Normally this would be a bad thing, but in this case, it is cause for celebration.
Well, since the start of ADISC we have been using a webserver in a fairly standard configuration. This has worked well for us up till now. Yesterday, however... we faced a situation we've never faced before. So many connections were made to the server at once, the webserver couldn't cope, and started rejecting new connections. That's why it gave the appearance of being down.
I've adjusted it upwards, so hopefully this shouldn't happen again.