It is not that it will not happen. But we need to prepare for the worst, just in case SMF main forum is down, you use the following link to get support. Don't worry, it is not a 3rd party site. The site belongs to SMF is a back up when the main site is down.

http://www.simplemachinesforum.org/community/

You need to register separately here to get support.

Why will such a good site be down ???
Hacking ?

There could be many issues that can cause a site non functioning. Main ones being server maintenance and hacking for big sites. In that case, they have the back up site.

See they are hacking the site ... then as the backup also in under the same domain they will have control over it also unless the files are on different server and the hacker doesnt have control over the domain.

I think they might have thought about it. Isn't the server that is hacked usually ? So being on same domain won't be a problem I think. And surely it will be on two servers as server maintenance is unavoidable at least once in a year.

Hmmm true.
That is what i was thinking unless they have it on a different server its almost impossible to stop it once the server is hacked.

I think they may have thought about this problem. Is not usually the server is hacked? Thus, in the same field will not be a problem, I think. Certainly will be two servers, server maintenance is inevitable, at least once a year.