Help with getting website back online

Not sure what happened, was updating the website, and then I got this message

Multiple Choices
The document name you requested (/index.php/trade-shows/ilmc-international-live-music-conference) could not be found on this server. However, we found documents with names similar to the one you requested.

Available documents:

/index.html/trade-shows/ilmc-international-live-music-conference (common basename)
/index.html3default1and1_bak/trade-shows/ilmc-international-live-music-conference (common basename) 

Now I get some default page from when you first install Concrete on your server and no way to log in. That said all my files still seem to be on the sever.

Looking for a expert…

My first guess here is that something has renamed index.php, to something else. Why, I can’t guess, but that might explain the error message.

Or, maybe your domain has ended up pointing somewhere else?