KEY POINTS:
San Francisco received a foretaste of the chaos that might occur following a big earthquake yesterday after an exploding petrol tanker truck caused the collapse of a key section of roadway leading up to the city's busiest bridge creating conditions for a perpetual traffic jam that could last for weeks or months.
The accident hit the San Francisco Bay area at perhaps its most sensitive point - a maze of roadways and ramps leading to the Bay Bridge which connects Oakland and Berkeley to the city.
The bridge is used by 270,000 cars every day and is a key lifeline for commerce as well as human traffic. Governor Arnold Schwarzenegger immediately declared a state of emergency.
City officials waived fares on public transport in an effort to get as many cars off the roads as possible. Engineers predicted it would take at least a month to repair the collapsed 170-ft stretch of freeway, and very possibly longer because of shortages in the world steel market.
Commuters, meanwhile, expected the worst and got something less than that - at least on day one - because they were all well informed on what had happened. Some people stayed home.
Others left for work early or postponed going in until later, to the point where traffic officials said they were looking at something close to a normal Monday morning.
Nobody, though, expected that to last. "It'll be a nightmare, an absolute nightmare," one train rider, Ron Chandler of Oakland, told the San Francisco Chronicle. "It really underscores how vulnerable we are."
The Oakland approach to the Bay Bridge is a notorious weak spot for several reasons. It is built on landfill rather than solid rock, which makes it prone to liquefaction during an earthquake - another way of saying that the ground can turn to jelly at a moment's notice.
During the last major earthquake to hit the area, in 1989, one section of the Bay Bridge itself collapsed and took months to repair.
Over and above San Francisco's vulnerability to tremors - it sits on two major faults including the San Andreas which runs the length of California - it is also a metropolis with many inbuilt vulnerabilities.
If the city's many bridges fail, then communication between Oakland and San Francisco, or between San Francisco and Marin County on the other side of the Golden Gate Bridge, becomes next to impossible.
Nobody was killed in Sunday's tanker truck accident, which highway patrol officials say was caused by the driver taking his load too fast around a corner. The petrol explosion sent flames shooting as high as 200 feet in the air. The truck driver was covered in second-degree burns and walked for a mile and a half to seek medical help.
The section of freeway that collapsed landed on another stretch of freeway intersection directly below, causing yet another closure. Not only does the accident compromise Bay Bridge traffic, it will also slow the flow of goods to and from the port of Oakland, one of California's biggest commercial hubs.
San Francisco is known to its many tourists as a singularly liveable American city, but its residents have increasingly struggled with transport and other problems in recent years.
The dot-com boom of the late 1990s and early 2000s brought much of the area's traffic to a standstill. The reconstruction of the eastern end of the Bay Bridge - first conceived as an earthquake protection measure but now widely regarded as a poorly planned, hugely expensive boondoggle - has already deterred many residents from crossing the Bay except when absolutely necessary.
That, in turn, has had an impact on businesses of all kinds on either side of the water.
- INDEPENDENT
