A big one, though not the big one: the earthquake scenario: despite the high level of earthquake preparedness in many parts of California, losses—both human and property—are still breathtakingly high when nature decides to shake things up with a magnitude 7.0 quake

Risk & Insurance, April 15, 2004 by Fouad Bendimerad

The Hypothetical Scenario:

Just after lunch on a summer Wednesday, more than 20 million people in Los Angeles feel the vibration underfoot. Immediately they know it is a major earthquake. Most people have felt distant or small tremors before. But this time they recognize the strong vibrations and the noise. The 30 seconds of shaking seems to last forever. This is no localized tremor.

High-rise office towers sway dangerously from side to side. Workers hold on to their computer equipment to prevent it from falling off their desks. Down below, drivers struggle to control swerving ears. After the sharing stops, there is a short silence. Outdoors, car alarms are going off across the city. Ta the south of downtown Los Angeles, a cloud of dust rises slowly into the Southern California sky. Office workers try to search the Internet for news but no sites are available. As they surf the Net, the power goes out. Many reach for their phones but the phone lines go dead. Cell phones show no networks are available. Managers walk through the offices telling everyone to go outside to their rally points.

News is coming through on car radios that the earthquake was a magnitude 7.0 centered in southern L.A. county, some 20 miles south of downtown Los Angeles. Some buildings have collapsed in the communities of Compton and Long Beach. Damage is being reported along stretches known as the Long Beach Freeway and the Harbor Freeway. Scientists from the United States Geological Survey have attributed the quake to a rupture of the northern segment of the Palos Verdes fault system. Emergency services rush to the area.

Coastal towns from Santa Monica in the north to Newport Beach in the south have suffered damage. The ground is deformed in many places and soft from steep slopes has slid into canyons.

EARTHQUAKE KILLS 400

Casualties are relatively light, given the amount of damage to buildings and infrastructure. A total of 400 people are feared dead and more than 3,000 people are injured. Many of them are employees injured in the workplace by falling equipment as well as collapsed partition walls and ceiling panels. Many people running out of buildings have been injured by falling debris. Ten people are reported to have been crushed in a shopping center by heavy building panels that came loose. Others are injured in car accidents. A few older structures have collapsed, including an eight-story office building occupied by a bottling company. Twelve people are pulled out alive, but another nine bodies are recovered. As many as 30 employees are missing. Search-and-rescue teams work into the night to cut through floors of pancaked concrete.

The high-rise buildings in downtown Los Angeles have escaped serious damage this time. But in the towns to the south and west, hundreds of thousands of buildings are damaged, including major commercial buildings. Tens of thousands more suffer lighter damage, but will require engineering surveys before they can be declared safe for occupancy. Repairs will take months. Many businesses face the challenge of trying to find suitable temporary office space.

PORT SINKS INTO ECONOMIC SLUMP

There has been extensive liquefaction and ground deformation around the port facilities. Areas around the Port of Los Angeles in particular are badly damaged. Container cranes, storage tanks and machinery rest at odd angles, as their foundations have slipped in the softened ground. Landings, berths and cargo terminals have also been damaged as their perimeter and retaining walls have moved and tilted. Bridges leading to Terminal Island are also closed pending detailed structural investigations. As all access to the port is impaired, non-essential workers are asked to go home.

The industrial areas of southwest Los Angeles Comity and Long Beach have suffered intense ground vibrations. The damage is heavy. Storage tanks and pipes have fractured. Emergency teams are dealing with hundreds of leaks. Minor fires are brought under control and extinguished. One fire in a tank farm takes two days to put out, even with dozens of firefighters. Some of the largest water treatment plants in the United States are badly damaged. There are reports of damage to power stations in Redondo Beach and Long Beach.

Los Angeles International Airport runways are cracked, and several terminal buildings have suffered damage. The crippled airport can only operate at very limited capacity.

With the exception of one section of the Harbor Freeway that slipped from its abutments, most of the major bridges appear to have remained in place, having been seismically retrofitted over the past decade. However, roadway cracks and differential settlement resulted in several arteries being closed to traffic in the southern part of the county. Faced with total gridlock, tens of thousands of drivers set out for the long walk home.

Electrical power is out across the whole city and is gradually restored to different parts over the next 72 hours. The Los Angeles central business district has power restored 24 hours after the earthquake. Managers attempting to restore business operations on Friday morning find, however, that they have no water services. Another day is lost.