Bluehost, HostMonster, HostGator, and JustHost suffered a massive outage. The outage seems to be related to server maintenance at the Provo, Utah data center.
HostGator set up a forum thread that provides information on the system outage. The companies are constantly updating their Twitter as some of their systems come back up.
Endurance International Group stated:
During the morning of August 2, 2013, Endurance International Group?s data center in Provo, UT experienced unexpected issues that impacted customers of bluehost, HostGator, HostMonster and JustHost. Company websites and some phone services were affected as well.
Many of our customers? sites are back online. Some customers may continue to experience intermittent access and slowness until services are fully restored. Customer should not experience any loss of data.