A network outage at hosting provider SAVVIS Communications has knocked a number of Web sites offline, including Web portal Lycos.

The outage occurred around 9 a.m. Eastern on Tuesday morning when a backup data line connecting SAVVIS's Boston data centers was accidentally severed, said Kathy O'Reilly, a Lycos spokeswoman. At the time, crews had been in the process of repairing the main line to the data center, which was also down, she added.

With the two data lines out of service, the entire Lycos Network including Lycos Mail and the Tripod Web hosting service was knocked off the Internet, O'Reilly said. None of the data being stored by Lycos was affected by the incident, she added.

"It's basically a cascade of failures," she said. "Several other companies in the Boston area have also been affected."

The Web sites of CIO magazine and CSO magazine were also knocked offline by the outage. (These magazines are both published by IDG, which owns the IDG News Service)

SAVVIS could not immediately confirm how many customers had been affected by the failure, but in a statement from the company's technical service department, sent out just before 3 p.m. Eastern, the company said that two of its data centers -- named B01 and B02 -- had been knocked offline.

"SAVVIS continues to work with the local Telco vendor and hardware vendor to restore connectivity," the statement said. "An estimated time of resolution is unknown at this time"

SAVVIS, based in Town & Country, Missouri, is one of the largest hosting providers in the U.S.