Facebook Goes offline

Facebook crashed this afternoon, leaving millions of users without access to the network.

The site, which has about 1 billion monthly users, displayed an error message to users who were trying to log on.

In a rare outage, visitors to the Facebook website just at about 4:33pm were greeted with a message reading "Service Unavailable."

Users of the Facebook mobile app also saw a network error.

The development sparked a spike in Twitter usage, with the hashtag #FacebookDown trending globally.

At 4:52pm, however, Facebook back online.