You may have noticed that some of your favorite websites went dark Tuesday afternoon. That includes LiveJournal, TypePad, Wired's blogs (but not Wired's main web site).

Turns out that's what happens when there's a major power outage in San Francisco where more than a few tech companies happen to be located.

More than 30,000 electric customers in the area lost power after an underground explosion. And while you would think big customers like oh, I don't know, Netflix would have a system in place to switch to a backup server if the main server goes down, the site was out for most of today.

While power hasn't been restored to all customers yet, several sites that were offline earlier today are back up and running, including Craiglist and Netflix. But this is the second time this week that we've heard of a massive internet outage. Coincidence? We certainly hope so.