In both the Japanese and San Francisco earthquakes, fire killed more people than collapsing buildings. This was probably a result of the both cities having most buildings constructed of wood, rather than a more fire proof material. The wood buildings fueled the fires rather than slowing them and trapped the people inside with no escape route. Although plenty of buildings collapsed during both earthquakes, fire is more lethal than debris and people could stay alive under rumble long enough until help came whereas the large fires in the cities made it hard for rescuers to keep people alive in burning buildings.