Item 26 - Adoption of the City of Santa Ana Emergency Operations Plan

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City of Santa Ana Emergency Operations Plan Part I Basic Plan 2.4.15 Urban Conflagration Definition and Causes Urban conflagration is a large fire occurring in an urban area that consumes multiple structures, with the potential to spread to whole neighborhoods or multiple locations. Although communities like the City of Santa Ana, without a wildland-urban interface, are much less likely to experience catastrophic fire, there are scenarios where the City might be exposed to urban conflagration. Causes of urban conflagration may include: • Criminal acts, such as arson, acts of terrorism, or civil unrest; • Industrial accidents, such as hazardous materials incidents, explosions, gas leaks, or transportation accidents (railroad crash, aircraft crash or trucking accident); • Acts of nature, including structure fires intensified by high winds or hot and dry weather conditions, wildfires driven into urban areas, or ignitions following a large earthquake. Although the risk to life and property from urban conflagration has been substantially reduced through improvements in community design, construction materials, and fire protection systems, it remains a threat. One reason is a continuing trend toward increased urban density and infill development. A post -World War 2 building boom resulted in the development of almost all developable land in the City by the 1970's. But the City's population increased by almost 140,000 people (approximately 70%) between 1980 and its peak in 2002 (near where it remains today). This growth was accommodated by near -total infill development (development of all vacant properties), an increase in multi -family or higher density housing, and renovation/expansion of existing structures. Approximately 80% of homes in the City were built in the 1970's or before, with approximately 55% built more than 50 years ago. This dense environment of structures built to older building code standards, with some maintained or renovated below building code standards, can contribute to the threat of urban conflagration. A variety of fire protection challenges exist in the City of Santa Ana. Among these are the high density of development; high rise buildings; large industrial or manufacturing complexes; hazardous materials transportation, use or storage; rail lines; a flight path to one of the busiest airports in the United States; and natural disasters. Urban Conflagration Scenarios The most likely scenario for urban conflagration in Santa Ana is a major earthquake in the area. Earthquakes may cause natural gas mains to rupture or cause damage to gas -fueled appliances in homes or businesses, may cause power lines to fall or electrical appliances to malfunction, and may cause fuel spills or release of flammable substances in homes or businesses. Large fires following an earthquake in an urban area are relatively rare, but have occasionally been of catastrophic proportions. The two largest peacetime urban fires in history, 1906 San Francisco and 1923 Tokyo, were both caused by earthquakes. With Santa Ana's dense and older construction, fires resulting from such earthquakes may cause substantial damage. The conflagration in San Francisco after the 1906 earthquake was the single largest urban fire, and the single largest earthquake loss, in U.S. history. The loss over three days of more than 28,000 buildings over an area of nearly 5 square miles was staggering: $250 million in 1906 dollars, or about $5 billion today. A more recent large urban fire occurred as a result of the Loma Prieta earthquake in 1989. 41 large fires occurred in the City of San Francisco after the quake. Gas main and pipe ruptures ignited 27 fires within the City, including a major blaze in the Marina District that destroyed four buildings and claimed the lives of five people. Damaged domestic water lines intensified the crisis. In 1991, a vegetation fire was driven into the Cities of Oakland and Berkeley by intense winds. The Oakland/East Bay Hills Fire claimed 25 lives, destroyed 2,449 single-family dwellings and 437 apartment/condo units, and caused economic losses estimated at $1.5 billion. 112