Sometime in the past 24 hours my site has just disappeared.

Here's the site: www.celestialtoystore.com

All I'm getting now is a blank page. I can't even access the Zen Cart control panel

My host tells me that the site is resolving properly but it may be a script problem on index.php.

I have not altered the script or touched it. Have I been hacked?

I'm using a modified 'End of Summer' template and it appears that other sites based on this template might also have gone skew whiff. When I log in using Filezilla, all the files appear to be there ok.

Any idea how I can get back up and running????