Hi,
Yes, today the site has loaded sometimes, and can be checked. There is the 500 Internal Server Error after loading Quickview, you can see this link http://take.ms/wWMOc. The cause may be your host. Please try to refer the link below.
http://techjam.gr/2012/magento/solve-magento-500-internal-server-errors/
This may solve your problem.
Thanks you,
