A PG&E power outage that extends from Dogpatch and Mission Bay to Twin Peaks has caused a rush-hour nightmare for Muni commuters as all Muni Metro service was stopped as a result.

PG&E has said they expect power to be restored by 10:30 a.m., but that isn't going to help the great many people who rely on Muni to get to work who are stranded and/or waiting for bus shuttles right now. As ABC 7 reports, an estimated 22,000 homes and businesses are affected, in addition to the Muni light-rail system. The map shown below also indicates that parts of Mid-Market, Upper Market and the Castro may be affected.

KCBS's Matt Bigler reports that the problem appears connected to PG&E's Substation A in Dogpatch.

So, for once it seems the Muni system itself is not to blame, but that is little consolation.

SFist will update you as this situation hopefully clears up. Godspeed, commuters.