Popular online knowledge trove Wikipedia was back online Monday after a fiber optic cable connection between its two US data centers was severed, causing an hour-long service outage. A cable line linking data centers in the states of Virginia and Florida was severed about 1300 GMT, according to the nonprofit Wikimedia Foundation, which operates Wikipedia.org and other websites. Wikipedia's websites were restored after an hour and the mobile service was back online by about 1535 GMT, Wikimedia said. "We are now working with our network provider to determine how and why we were impacted by that fiber cut when we are supposed to have redundancy in our network," Wikimedia said in a blog post. "We are still waiting for their full report." Wikimedia has two separate fiber optic lines connecting the data centers, with one connection intended to act as a backup for the other in event of a problem. The data center in Virginia handles most Wikipedia traffic but accesses the center in Florida to fetch stored information in the crowd-sourced online encyclopedia, according to Wikimedia.