At 5:04 PM on Tuesday, October 17, 1989, a magnitude 7.1 earthquake centered near Loma Prieta Peak in the Santa Cruz mountains of northern California caused 62 deaths and 3,000 injuries (14). The Loma Prieta earthquake was this country's most damaging earthquake since the 1971 San Fernando Valley earthquake in southern California. The Loma Prieta earthquake brought to memory the December 7, 1988, earthquake in Armenia, which, although about one-half its size in terms of energy release (magnitude 6.9), caused an estimated 25,000 deaths and 18,000 injuries. The differences in impacts between these two earthquakes is directly related to differences in the degree of disaster mitigation and disaster preparedness measures taken in northern California and in the former Soviet Union (15-17). Strict adherence to building codes during the past two decades in the San Francisco Bay region undoubtedly saved many lives and kept thousands of buildings from collapsing in the Loma Prieta earthquake (18-20).

With population increases and rapid urbanization in seismic- risk zones, earthquakes producing high numbers of casualties are expected to continue to occur in the future. Other factors affecting earthquake-related morbidity and mortality will be discussed in more detail in the next sections of this chapter.