The two Strange servers and the Hotel server are currently down due to what appears to be a hard drive failure.

The dedicated server machine we use has two hard drives, one of which hosted those 3 servers. That hard drive appears to have died meaning we can't boot those servers up right now.

I have opened a support ticket with our host who are investigating as of the time of writing.

[Update]
A new hard drive has been installed but unfortunately the data on it was lost, meaning I will have to re-install all 3 effected servers.

Thankfully we have backup builds of those servers so bar some minor updating of plugins, we should be able to get them back up fairly quickly.

The remaining servers are back online as well, as the hosts needed to turn them off while installing the new drive.