Preparing for the "Big One" -- Saving Lives Through Earthquake Mitigation in Los Angeles, CA

At 4:31 a.m. on January 17, 1994, a 6.8-magnitude earthquake struck a densely populated area of Los Angeles near the community of Northridge. More than 30 people were killed in the tremor; a total of 61 deaths were attributed to direct and indirect causes. In the following 3 weeks, the region was rattled by more than 2,500 aftershocks. By the time the seismic activity subsided, at least 65,000 residential buildings had sustained damage; essential local facilities and services had been seriously disrupted as well. The State of California has estimated total damage at between $18 billion and $20 billion.

The Federal Government immediately mobilized to help the citizens of the Los Angeles area meet the emergency and begin to rebuild their lives and communities. Staff and resources from numerous Federal agenciesincluding the Federal Emergency Management Agency, the Small Business Administration, the armed forces, and the U.S. Departments of Transportation, Health and Human Services, and Housing and Urban Developmentwere quickly dispatched to the affected area. By June 30, an estimated $5.2 billion in Federal funds had been obligated to earthquake response and recovery activities and it was expected that an additional $6.7 billion would be committed in the near future.

Although the deaths, injuries, and damage caused by the Northridge earthquake were terrible, the toll probably would have been much worse if the quake had not occurred in the pre-dawn hours of a holiday, when most people were in their beds. This event was a harsh warning that can only be ignored at the risk of untold thousands of lives. However, there is much that can and should be done to help at-risk communities minimize loss of life and property in the next major earthquake. This report is intended to support such efforts by placing actions already underway in the context of the Los Angeles area's most essential earthquake mitigation needs and describing mitigation strategies that would save lives when, inevitably, the big one strikes.

Focusing on Mitigation

Repair and rehabilitation activities in the aftermath of the Northridge disaster are only half the challenge. These are primarily intended to rebuild lives; the goal of mitigation is to save lives. Recovery efforts that merely recreated pre-earthquake conditions would be at best a temporary palliative the risk to life and property in a future disaster would remain undiminished and, indeed, all the more tragic for being preventable. Mitigation is intended to achieve a higher level of safety. It encompasses policies and actions taken before an event to minimize the effects of damage and injury when an event does occur. It also includes strengthening buildings that may have escaped damage in a previous disaster.

Of course, mitigation and recovery are not entirely distinct from one anotherrather, they are two parts of a single continuum. Mitigation is often presented as one of four phases in the cycle of disaster planning (Exhibit 1). In practice, it overlaps with the recovery period, which many assert is the best time to initiate mitigation strategies. Preparedness activities also can be considered as one aspect of mitigation. Thus, mitigation should be an ongoing, comprehensive process.

Los Angeles was spared much worse damage and loss of life in the Northridge earthquake through a combination of preparedness and luck. The area benefited from California's long experience with earthquakes and from the combination of laws, public programs, and private preparedness that limited damage and enabled critical systems and services to function effectively in the emergency. Nonetheless, additional injury and loss of life was averted by mere chancethe major shock occurred at a time when schools, businesses, and roads that sustained serious damage were largely deserted.

This report is organized into six sections. The first describes the existing array of Federal, State, and local earthquake mitigation efforts available in the City and County of Los Angeles. The four succeeding sections review information on earthquake damage and mitigation needs for essential elements of the area's urban environment housing, hospitals, schools, and lifelines. Each of these sections also discusses the current status and estimated cost of mitigation efforts. The report concludes with a discussion of gaps in the existing mitigation system and explores steps to support mitigation-related efforts in Los Angeles and other at-risk areas.

Extensive interviews were conducted to draw on the experience and insights of persons directly involved in earthquake recovery and mitigation efforts, including Federal, State, and local government officials, as well as representatives from utility companies and other private and nonprofit institutions in the Los Angeles area. In addition, information for this report was compiled from news articles, published research on mitigation technology and the experience of other earthquakes, as well as from recently published assessments of the damage caused by the Northridge quake.

Hospitals and Emergency Health Care

Sixty-one people were killed and over 8,700 were injured in the Northridge earthquake, including more than 1,600 people who required hospitalization. Hospitals and health care facilities experienced both structural and nonstructural damage that impaired their ability to protect occupants during the earthquake and to treat earthquake victims afterwards. Eleven hospitals were completely or partially closed, and their patients evacuated, due to earthquake damage.

The six acute hospitals and 44 health centers operated by the Los Angeles County Department of Health Services are the primary provider of basic health care services to the Los Angeles area and often the only provider for the medically indigent population. Major earthquake mitigation needs at these facilities range from replacement and retrofitting activities intended to ensure seismic safety, to enhanced communication systems and expanded trauma facilities that will improve the capacity to respond to emergency medical needs in future disasters. The total cost of seismic upgrades to Los Angeles County's public hospitals and health centers is estimated at $2.3 billion. Cost estimates for additional improvements are not yet available; nor are estimates for the mitigation needs of hospitals and medical facilities outside the Los Angeles County system.

Schools

If the Northridge earthquake had struck during school hours, thousands of children would have been injured or killed by falling debris, furniture, and lighting. For 4 days after the earthquake, classes for the 640,000 students in the Los Angeles Unified School District were cancelled. Damage to school buildings left 250,000 children temporarily without classrooms. Nonetheless, all but 75 of the District's schools reopened within a week. Three weeks after the earthquake, only 21 schools remained closed. The total cost of damage to public schools is currently estimated at between $150 million and $200 million.

Overall, Los Angeles public schools withstood the Northridge earthquake remarkably well, due in large part to the stringent school construction code enacted by the California legislature in 1972. Structural damage to schools was minimal, although cracked foundations were severe enough in two cases to require demolition of the buildings. Approximately 10 percent of the Los Angeles Unified School District's school buildings require structural mitigation. Officials calculate that 35 lift-slab buildings, 572 masonry buildings, and 515 concrete buildingsall constructed before 1972 are in need of some structural retrofitting. The District estimates that this work would cost $786 million.

However, local and State officials have identified nonstructural retrofitting as the more pressing mitigation need. The Northridge earthquake made clear that nonstructural hazards notably the collapse of suspended ceilings and lighting systems pose a greater safety threat than structural weaknesses at this time. School officials estimate that retrofitting lights and ceilings alone will cost approximately $297 million.

Residential Structures

To minimize loss of life in residential structures, particular attention should be given to retrofitting unreinforced masonry buildings (URMs), wood-frame homes, and hillside homes, as well as to anchoring manufactured homes and strapping gas water heaters. As of April 4, 1994, approximately 65,300 residential buildings in the City of Los Angeles, containing 308,900 units, were known to have sustained damage in the Northridge earthquake. Multifamily units suffered the most damage: 258,937 of the damaged dwellings were multifamily units and 49,909 were single-family homes. The cost of the damage has been estimated at over $1.3 billion; however, private insurance claims may be as high as $8-$11 billion.

Wood-frame buildings made up the vast majority of structures damaged in the earthquake. In particular, multi-story buildings with a "soft" first storyusually consisting of wood-framed parking facilitiesperformed poorly, in some cases putting occupants at serious risk. These facts have troubling implications for the urban areas of Los Angeles, where the majority of the multifamily housing stock is three- and four- story wood-frame construction. The collapse of the three-story Northridge Meadows apartment building, which killed 16 people, is a tragic example of wood-frame failure. Single family wood- frame homes with cripple-walls are also vulnerable. Mitigation costs for the estimated 100,000 single family homes within the City of Los Angeles requiring cripple- wall retrofit would range from $200 million to $400 million, compared with $3 billion for repairing the same number of damaged buildings.

Unreinforced masonry buildings are considered the building type most vulnerable to earthquake damage. However, retrofitting has proven to be very effective in mitigating damage properly retrofitted unreinforced masonry buildings experienced far less structural damage than those buildings not retrofitted. Although many have already been retrofitted under a local seismic safety program begun in 1981, about 500 unreinforced masonry buildings, most of which are commercial and mixed use properties, still require work at an estimated total cost of between $75 million and $225 million.

Homes built on steep grades of more than 20 percent are also vulnerable in a seismic event. The Northridge earthquake damaged 400 hillside homesin two instances, residents died in the collapse. Although the total number of homes constructed on hillsides is unknown, one informed guess puts the number at around 10,000 single-family dwellings, with the total retrofit cost in the range of $60 million to $250 million.

A lack of bracing was often responsible for seismic damage to manufactured homes. When the earthquake knocked manufactured homes off their foundations, gas supply pipes often ruptured, causing fires that could easily spread to nearby homes. The cost of anchoring Los Angeles' 9,000 manufactured homes would be approximately $45 million.

Gas water heaters also pose a fire hazard in both manufactured and site-built housing under seismic conditions. According to the Southern California Gas Company, 40 percent of all structure fires during the earthquake was caused by water heaters breaking away from their gas supply even though any new water heater installed since 1984 is required by law to be strapped. The cost of properly securing a water heater to prevent failure and fire during an earthquake is approximately $100. Based on an upper bound estimate, providing all of the approximately 512,000 single-family detached units in the City of Los Angeles with proper water heater bracing would cost $51.2 million.

Lifelines

Broken lifelines posed serious threats to human life and public health safety in the aftermath of the Northridge earthquake. Ruptured gas mains fed over 100 fires and disrupted service. Approximately 100,000 customers lacked potable running water immediately after the earthquake. The tremor also damaged electric power stations and power lines, leaving more than 2.5 million southern California customers without electricity. Although the quake caused significant damage, the utility industry has concluded that power, water, and gas systems recovered exceptionally well after the Northridge earthquake. Within 10 days, fewer than 100 scattered customers remained without water service. Most customers had electricity again within a few hours, though a few were without service for more than 2 days.

A prime culprit in many of these utility system failures was older pipelines and substations, built before World War II to outmoded standards. The Los Angeles Department of Water and Power reports that it must replace 20 older substations in downtown Los Angeles at a total cost of $220-$320 million. It estimates that replacing 300,000 feet of pre-1940 trunklines in the water piping system will cost another $300 million.

Collapsed roads and bridges also threatened lives and recovery efforts. Infrastructure failure directly caused at least one death and several injuries to motorists when the Northridge earthquake struck. Damaged highways also created tremendous problems in the delivery of essential services. Although most of the 600- mile Los Angeles freeway system survived the Northridge earthquake, extensive damage or collapse closed 10 freeway structures and caused widespread disruptions in the following weeks. Current estimates by the California Department of Transportation set total highway damage at $334 million. Retrofitting all damaged and undamaged bridges in Los Angeles and Ventura Counties that fail to meet current seismic safety standards would require an estimated $500 million.

Addressing Gaps in the Earthquake Mitigation System

Despite the new resources identified and the new partnerships formed in the aftermath of the Northridge earthquake, serious gaps and deficiencies in the array of existing programs and resources limit the scope and effectiveness of earthquake mitigation efforts in the Los Angeles area.

The most fundamental problem is the short duration of our efforts to reduce earthquake hazards. Ongoing mitigation efforts are needed. Current Federal mitigation efforts are actually a form of post-disaster response and recovery. The primary source of long-term mitigation funding the Federal Emergency Management Agency's (FEMA's) Hazard Mitigation Grants Programcan only be tapped after the President has made a major disaster declaration. Limiting assistance for long-term efforts to the recovery period, when attention is most focused on short-term needs and solutions, may work against effective mitigation.

State and local efforts to mount needed mitigation efforts may have been slowed by Federal program rules that make it difficult to apply some forms of assistance to mitigation or to coordinate their use with other public and private funds. Relevant Federal assistance programs should be reviewed to identify and reduce barriers to their use in disaster recovery and mitigation. Even before the Northridge earthquake, HUD launched a review intended to assess and remove obstacles to the use of CDBG and HOME for mitigation-related activities. More recently, FEMA convened an interagency Mitigation Task Force in November 1994 to develop a coordinated Federal Mitigation Plan.

Attempts at the State and local level to address the need for ongoing mitigation are too often frustrated by an inability to obtain the necessary funds. Although Hazard Mitigation Grants and other FEMA programs offer significant funding for repairs and mitigation, these grants are conditioned upon the eligible State or local entity matching at least some percentage of the amount. In California's climate of strict fiscal austerity, raising revenues to leverage Federal funds and operate State and local mitigation programs has been extremely difficult. In the months following the Northridge earthquake, one bond issue was rejected by voters and another died in the State legislature. As of early August 1994, State and local agencies lacked the funds to fully match available FEMA funds.

Without adequate public and private funding, it is also very difficult to enlist property owners in mitigation efforts. Although mitigation reduces the likelihood and cost of future damage, incentives can be essential to making mitigation attractive to property owners. Financial incentives should be considered to encourage continuing private sector participation in mitigation activities. Inducements such as discounted insurance premiums, tax credits, low- or no-interest loans, mortgages, and grants would make mandatory mitigation measures more palatable, as well as easier to enforce.

Mitigation efforts in Los Angeles also suffer from deficiencies in other types of essential resources. Further research on the seismic performance of various types of construction and on new building materials and methods is needed in order to strengthen building codes and encourage improved design and construction. Effective mitigation planning also demands reliable knowledge of the local building stock. However, the City of Los Angeles does not possess an accurate assessment of the number or construction type of the buildings within its boundaries. A complete, automated inventory of the Los Angeles building stock is needed. While city records contain a wealth of valuable information on residential structures, for example, data covering over 840,000 individual parcels can only be managed and analyzed efficiently with an automated system.

Chronic fiscal distress has also compromised State and local governments' inspection ability to ensure the seismic safety of buildings, public facilities, and infrastructure. Staff reductions at agencies responsible for hazard monitoring, as well as a lack of resources for professional development of local building and infrastructure inspectors, have contributed to a troubling degradation in inspection capacity. An adequate staff of qualified and properly trained inspectors, equipped with the resources to carry out their responsibilities, is needed at key State and local agencies to ensure vigorous enforcement of construction and seismic safety standards. To carry out their responsibilities, building inspectors must be trained in the most recent codes and principles of seismic design.

Expanding and Sustaining Mitigation Efforts

An aggressive, ongoing campaign of mitigation activities is needed to place the safety of Los Angeles area residents on a firmer footing. It is estimated that the cost of earthquake mitigation to residential buildings and essential facilities and systems will exceed $5 billion. However, even this figure almost certainly understates the total cost because estimates are still needed for some key mitigation activities.

Although Federal agencies mobilize vast resources to assist in response and recovery efforts after disasters such as the Northridge earthquake, the findings of this report strongly suggest the need for even more vigorous support for mitigation strategies that can save lives. Certainly, the Federal Government has an important role to play in creating a safer and more resilient Los Angeles. The Administration is in the process of developing a set of natural disaster reform initiatives, including pre-disaster mitigation reforms. These reforms will be submitted to the Congress.

Inevitably, though, the greatest responsibilities and the greatest resources are to be found at the local level. As this report will show, the creativity and determination of local residents, State and local governments, public and private institutions, and community-based organizations in the Los Angeles area has already stimulated many important mitigation efforts. However, the most critical challenge still lies ahead.

Leadership from many quarters will be needed to sustain earthquake mitigation initiatives in the coming months and years, as more tangible needs compete for attention and resources. It is easy to feel powerless before the threat of a force so unpredictable, physically overwhelming, and emotionally incomprehensible. But while people cannot begin to control the timing or the cataclysmic power of the next earthquake, mitigation can give them some measure of control over its impact on their lives, safety, and property. Therefore, preparing for the big one must continue to be an urgent public and private priorityfor every action taken to upgrade a home or business, and every dollar spent to build a safer school or road, may mean lives saved. But just as surely, every action deferred and opportunity squandered may one day be reckoned in lives lost.