The power outage affected areas from this city to the northern edge of Silicon Valley, snarling airport activity and creating monster traffic jams both on surface streets and in cyberspace. The outage also ceased trading at the Pacific Stock Exchange, which closed for the day, sending equity and options orders to its Los Angeles arm.
Pacific Gas & Electric estimated that the blackout affected 370,000-plus bill-paying customers, a figure that translated into numbers approaching 1 million, according to estimates by public officials. The utility said it had restored power to all but 20,000 customers by midafternoon, several hours after the outage began at 8:17 a.m.
"I've lived in the Bay Area for three decades, and I've never seen anything like this," PG&E spokesman Chris Johnson said of the blackout, which began at a substation south of San Francisco and triggered outages at other facilities in an electrical domino effect.
The public utility, which supplies power to cities and counties throughout Northern California, blamed the problem on a "simple human error" stemming from construction work in the city of San Mateo. PG&E chief executive Gordon Smith said the construction error involved a single piece of copper pipe and said the utility had no back-up systems in place.
Although the outage was limited to the San Francisco region, its effects knew no geographic boundaries in cyberspace. The blackout affected vast numbers of people and companies that use the Internet everywhere, many of which rely on communications with the Bay Area and operations based here, regardless of where they themselves are physically located.
PG&E said it would review compensation claims for business lost to the power failure. "Claims will be handled on a case-by-case basis," said a statement posted its Web site at the end of the day.
A number of Web and e-commerce companies went dark or were forced to use back-up power systems when the blackout struck. Electricity at the offices of CNET: The Computer Network was out this morning, temporarily disabling the company's servers, including those used by News.com and Snap.
Some companies had backed up their servers outside the Bay Area, allowing them to weather the outage better than others. Such was the case for online brokerage E*Trade and the Web operations of San Francisco-based Charles Schwab.
CompareNet, which has offices based in San Francisco's China Basin area, was able to continue its online operations because its site is hosted at Web hosting firm Frontier Globalcenter in Sunnyvale. Nevertheless, the outage downed internal servers at CompareNet, preventing it from updating its site, making changes to its database of consumer price-comparison information, or launching a scheduled banner ad campaign.
"The site was on autopilot," company president Trevor Traina said. "It's amazing to me that the world's most productive and technologically advanced region was brought to its knees because one guy somewhere made a mistake."
Most Internet service providers reported few disruptions in service. "We had to go on back-up power using a diesel generator, but we didn't blink at the outage," said Mike Lydon, director of network operations for Best Internet, a major Web hosting operation whose San Francisco office was hit by the blackout.
IGC Netcom switched customers dialing into its one San Francisco point of presence (POP) to other connections. Pacific Bell Internet resorted to back-up power, but Concentric Network reported no problems with its lines.
"Modems are on and answering, although you may not be able to login yet. Mail and news should be up and running. We will keep updating as information becomes availible. Sorry for the inconvenience. Have a good day," the message concluded.
A toll-free tape-recorded message at the ISP offered a similar explanation.
The outage did not extend far south enough to affect most Silicon Valley businesses. "They had a blink of the eye when the hit came, but they didn't lose power," PG&E spokesman Scott Blakey said.
Stanford University, which hosts a major Internet hub that has had problems with power surges in the past, experienced no interruptions. In fact, its own power-generating facility supplied power to PG&E during the outage.
Major banks go offline
Still, companies that rely on other services based in San Francisco, such as banking, were affected by the outage. Bank of America and Wells Fargo reported disruptions at their branches and with their automated teller machine networks. Wells said that the lack of power forced 113 branches to close but that credit card operations continued, though phone authorizations were required in areas where the power was out.
Companies were also hampered because many employees couldn't get to work. Traffic lights in much of San Francisco were out, slowing movement on city streets to a crawl. Traffic into the city from Oakland and the South Bay also was jammed as vehicles exiting the freeways ran into snarls.
The blackout halted public transit systems in the area, including the underground BART commuter rail that links San Francisco to Oakland and other parts of the Bay Area. Within San Francisco, electric trolleys and cable cars were out of service in many areas, as were the underground Metro trains.
The outage, which prompted San Francisco Mayor Willie Brown to declare a citywide state of emergency, took at least two local television stations and several radio broadcasts off the air.
The outage served as a reminder of the kinds of disruption the power-reliant information industry could face in the year 2000. Some predict that the so-called Y2K bug, the result of common computer date fields that do not distinguish between the years 1900 and 2000, will cause greater power failures and other infrastructure problems.
Outages pose a special risk to computers and other sensitive electrical appliances because of surges that occur when power is restored. Homes or businesses located in close proximity to transformers--hardware on the power line that connects a building--are at particular risk.
As a result, power companies recommend the use of surge protectors. They also recommend that, during a power outage, sensitive appliances be unplugged and main breakers be switched off.
Reuters contributed to this report.