A fire in a Seattle data center Thursday knocked out a portion of Microsoft's Bing search engine and hundreds of other Web sites for as long as 36 hours over the holiday weekend.

According to the operators of the data center, called Fisher Plaza East, the fire began after "an incident in a garage-level electrical room" at around 11:10 p.m. Thursday night knocked out the data center's backup generator. Fisher Plaza East receives its power through this room from Seattle City light, the company said.

Among the Web sites and services knocked offline were Seattle's KOMOnews.com; Verizon's DSL service; Authorize.net, which processes credit card transactions; MotherJones.com and Allrecipes.com. A partial list of affected sites is at this blog.

Microsoft's Bing Travel site was out the longest, according to the Seattle blog TechFlash and did not return until around 11 a.m. Saturday, nine hours after power to the data center was restored.

A Microsoft spokeswoman told TechFlash that Microsoft hadn't finished migrating the travel site's servers to the Microsoft Cloud Computing Platform, presumably housed in its own data centers. The rest of Microsoft Bing wasn't affected by the fire, but the travel site is based on an acquisition, Farecast, that Microsoft made last year.

TechFlash also said that this isn't the first outage at Fisher Plaza East. The Seattle data center also went offline last year after an electrical fire.

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