Not Found – suddenly – all pages

I did: searched everywhere for how to fix but nothing is working. deactivated plugins, checked to make sure posts and page content did not get unpublished, checked permalinks settings (not changed and it was working fine), changed permalinks to see if that helped (it didn’t / we have been using %postname% for some time), checked various .php files against same files on blogs that are working…can’t fix.

I saw: Not found errors on all pages, RSS, etc. Initially I also got page not found for the admin page, but deactivating 2 plugins via FTP allowed me to get into admin and see that the content is there. My colleague tells me a successful post was made on July 24. She remembers previewing it. The wp-config file has not been changed since the site was working. htaccess looks fine although I saw a fix on a site about changing 644 to 666 and I see no relation to the htaccess page content I see. It points to the correct URL. No changes at the host end. All info about the host looks fine. We noticed the blog pages down on August 1 but it could have been down any time after July 24.

I expected: To find a solution in google, forums, here, and cannot find. Exhausted my options. Please help me present this blog content again: yougetwhatyoumeasure.com/SecurityFirst/wordpress. Our other blogs are still working fine. -Lori