<P> As damaging as the earthquake and its aftershocks were , the fires that burned out of control afterward were even more destructive . It has been estimated that up to 90 % of the total destruction was the result of the subsequent fires . Within three days , over 30 fires , caused by ruptured gas mains , destroyed approximately 25,000 buildings on 490 city blocks . One of the largest of these fires was accidentally started in a house on Hayes Street by a woman making breakfast for her family . This came to be known as the `` Ham and Eggs Fire '' . Some were started when firefighters , untrained in the use of dynamite , attempted to demolish buildings to create firebreaks . The dynamited buildings themselves often caught fire . The city 's fire chief , Dennis T. Sullivan , who would have been responsible , had died from injuries sustained in the initial quake . In all , the fires burned for four days and nights . </P>
most of the destruction in san francisco following the earthquake of 1906 happened due to
fires