Image: Grant Avenue after the earthquake in San Francisco.
by Chris Frantz
At 5:12 a.m. on 18 April, 1906, the people of San Francisco were awakened by an earthquake that would devastate the city.
The main tremor, having a 7.7–7.9 magnitude, lasted about one minute and was the result of the rupturing of the northernmost 296 miles of the 800-mile San Andreas fault.
But when calculating destruction, the earthquake took second place to the great fire that followed.
The fire, lasting four days, most likely started with broken gas lines (and, in some cases, was helped along by people hoping to collect insurance for their property—they were covered for fire, but not earthquake).
With water mains broken, fighting the fires was almost impossible, and about 500 city blocks were destroyed.
The damages were estimated at about $400,000,000 in 1906 dollars, which would translate to about $8.2 billion today.
Uncertain Death Toll
In 1906 San Francisco was the ninth largest U.S. city with a population of 400,000, and over 225,000 were left homeless by the disaster. The death toll is uncertain.
City officials estimated the casualties at 700 but more modern calculations say about 3,000 lost their lives.
The lowballing city figures may have been a public relations ploy to downplay the disaster with an eye on rebuilding the city.
On 20 April, the U.S.S. Chicago rescued 20,000 victims, one of the largest sea evacuations in history, rivalling Dunkirk in World War II.
Martial law was not declared, but some 500 looters were shot by police and the military.