Originally Posted by fabin
Try disabling all plugins and check if that brings the site back.
Ahhh - yes, I needed that sanity-check. Why hadn't I thought of this previously?
I will go and do that - although I have no doubt this will bring the site back. This client is running an obscure and very messy plug-in that does "passive blogging"
Tactics - the client has not edited any files, and the site was indeed working early today.
Thanks for the sanity check ... I expect to be back with more questions