Occupant's Location Within a Building

In several past earthquakes in the United States and in other countries, the location of people at the time of the earthquake's impact has been shown to be an important determinant of morbidity. For example, the morbidity and mortality rate was significantly greater for people who were indoors than for those who were outdoors when earthquake shaking began (33,65,76,83).

Furthermore, occupants of upper floors of multistory buildings have been observed to fare less well than ground-floor occupants. For example, in Armenia, there was a significant "dose-response" increase in risk for injury associated with the building floor people were on at the moment of the earthquake. People on the second to the fourth floor at the time of the earthquake were 3.84 times more likely to be injured than those on the first floor, and those on the fifth floor and higher were 11.20 times more likely to be injured (65).

Four out of five deaths in the Loma Prieta earthquake occurred in motor vehicles on public roadways (14). As in nonearthquake situations, where motor vehicles account for more than half of unintentional injury deaths (84), occupants of motor vehicles appear to have a special risk of fatal injury in an earthquake. As mentioned above, in the Loma Prieta earthquake, a single circumstance, the collapse of the Cypress Viaduct of Interstate 880 in Oakland, accounted for 40 of 62 total earthquake-related deaths.