If you’re wondering why a bunch of popular Internet sites are down, its because of a power outage at PG&E at the center of the SOMA district in San Francisco where many of the new companies are located.

Craigstlist, Technorati, Yelp, Six Apart’s TypePad, LiveJournal and Vox are among those affected. Between 30,000 and 50,000 PG &E customers in San Francisco and the northern Peninsula lost power for several hours this afternoon after a reported explosion near Mission street. Craigslist is still down for us.