Please keep in mind that just because you cannot reach your website, it might only be down for you. We have firewalls on our systems that will automatically block people (for 15 minutes) if they fail their login too many times.
We do this for your protection, so people can't try to guess your passwords. If you cannot reach your site or cPanel, the best way to figure out if the server is down is by going to http://downforeveryoneorjustme.com and putting in your domain name.