San Francisco residents were abruptly awakened one spring morning by an earthquake that lasted no more than a minute, but set off a chain of events that caused the city to burn for four straight days. The estimated 7.7- to 7.9-magnitude temblor not only broke natural gas mains, which sparked the fires, but also damaged water mains, leaving the fire department with limited resources to battle the blaze. By the time the fires were doused, flames had devoured more than 500 city blocks.
San Francisco earthquake and fire, looking toward the Ferry Building, 1906. Over 225,000 of the city’s 400,000 residents were homeless. Fires destroyed about 28,000 buildings and 500 blocks – ¼ of San Francisco.