The outage began at about 8:20 a.m (1620 GMT), and by 10 a.m. (1800 GMT) , December 8, 1998, the San Francisco Office of Emergency Services reported that 250,000 San Francisco PG&E customers were without electricity. Another 120,000 on the Peninsula were also affected. San Francisco OES reported a major transmission outage affected parts of the Northern Peninsula as well as the southeast and eastern parts of San Francisco. PG&E has identified a substation in San Mateo operating in an under-frequency situation this will cause substations to shut down.PG&E said power was restored to the City by 2:05 p.m., however some small pockets remained of the outage, including the Twin Peaks area and sections of Army Street also known as Cesar Chavez Street. PG&E said all power was to be restored to San Francisco by 5:30 p.m.
The Associated Press estimated the number of people in the blacked-out area at 938-thousand. AP also quoted PG&E president and CEO Gordon Smith as blaming the power failure on simple human error, when a construction crew at a San Mateo County substation made a mistake with a temporary ground.
PG&E, in a news release, said:
At approximately 8:15 a.m. today, a major outage originated at PG&Es San Mateo Substation. The outage affected approximately 375,000 customers from San Mateo north to, and including parts of, San Francisco.
The cause of the outage was simple human error, which then triggered a complex sequence of events.
The Mayors office of San Francisco and the various department heads for the City have provided both guidance and assistance in ensuring San Francisco residents and businesses come back on line as fast as possible. With the full cooperation of the City, we have been able to restore power safely, effectively and quickly.
Full restoration of power to affected customers was completed this afternoon by 2:15 p.m.
Claims will be handled on a case-by-case basis. Customers who have legitimate claims to make can click here for claims information or call Customer Service at 1-800-PGE-5000.
In San Francisco, all streetcar, MUNI Metro and cable car service stopped, as did the trackless trolleybuses. MUNI pressed motorized vehicles into service on affected lines, and suspended fare collection until midnight. San Francisco police also evacuated MUNI patrons trapped in the streetcar tunnel between Twin Peaks and the Embarcadero. All MUNI Metro stations were closed, and BART service to the East Bay was suspended when the Transbay Tube was closed.
A San Francisco Fire Department inspector told the Associated Press that people were reported trapped in elevators in at least 50 highrise buildings in downtown San Francisco.
The California Highway Patrol reported major backups on freeway offramps in San Francisco because all traffic signals were knocked out by the outage. San Francisco police officers and Department of Parking and Traffic personnel were directing traffic at blacked-out intersections. All tow-away regulations were suspended because of the blackout.
Police also asked people not to call 9-1-1 unless they were involved in an emergency situation, and to give emergency response vehicles the right of way on clogged city streets. The 9-1-1 Center recalled one-half of its off-duty staff to report to work. The San Francisco fire alarm box and the Mayors Emergency Telephone Systems (METS) remained in full operation.
The Public Utilities Commission said low water pressure was reported in some neighborhoods because 12 pumping stations were running on emergency power and four stations were without any power. Power was reported out at the Oceanside and Southeast water treatment plants.
PG&E reported to the San Francisco Emergency Operations Center that power had been restored to all substations, and the next link will be to restore power to users. Power was back on to City Hall, the Department of Public Health building at 101 Grove, and to the Hall of Justice as of 11:40 a.m.
Areas already with power as of 12:45 p.m.:
All City emergency communications systems operated on generator power, and there was no interruption of emergency services. San Francisco Police canceled all non-essential runs for the duration of the outage.
Schools were asked by the City to remain open, and students were to remain there until released to a family member or a guardian.
A few flights at San Francisco International Airport were diverted to other airports when the massive outage began, and flights at midday were backed up from one to two hours.