What process caused the greatest number of fatalities during the 1994 Northridge, California earthquake?

    *  Great chasms opened in the Earth and swallowed people whole.
    *  Large objects (like buildings and highway overpasses) fell on people.
    *  Fires erupted following the earthquake, trapping many people in burning buildings.
    *  City sewer systems failed causing epidemics of diseases like cholera and typhoid.