1906 San Francisco Earthquake and Fire: A City Destroyed

The 1906 San Francisco earthquake struck at 5:12 am on 18 April 1906, when the San Andreas Fault ruptured along about 477 km (296 miles) of the northern California coast. The shaking, estimated at magnitude 7.9, damaged buildings across the region, and the fires that followed burned for three days and destroyed most of San Francisco. At least 3,000 people are now believed to have died, and the disaster became a turning point in the science of earthquakes.

Background: the city by the bay

In 1906 San Francisco was the largest and wealthiest city on the west coast of the United States, with around 400,000 people. It had grown rapidly since the California Gold Rush of 1848-1849 and was the financial and shipping centre of the Pacific coast. Much of the city was built of wood, and parts of the waterfront stood on filled land reclaimed from the bay.

Earthquakes were familiar in California. A strong earthquake had damaged San Francisco in 1868, but scientists did not yet understand how faults worked. The San Andreas Fault had been identified in part, but its full length and significance were not appreciated.

What happened

The earthquake

At 5:12 am on Wednesday 18 April 1906 a foreshock was felt, followed some 20 to 25 seconds later by the main shock. The epicentre was offshore, close to San Francisco. The rupture spread north and south along the San Andreas Fault, from near San Juan Bautista to Cape Mendocino.

Strong shaking lasted roughly 45 to 60 seconds. Along the fault the ground was offset horizontally by up to about 6 metres (20 feet) in places, splitting roads, fences and trees. The shaking was felt from southern Oregon to Los Angeles and inland as far as central Nevada.

Damage was worst on soft, filled ground near the bay, where the soil liquefied and buildings sank or collapsed. Towns along the fault, including Santa Rosa, San Jose and Palo Alto, also suffered heavily. At Stanford University several buildings were wrecked, and in Santa Rosa much of the town centre was destroyed.

The fire

The earthquake was followed by a far greater disaster. Damaged chimneys, overturned stoves and lamps and broken gas lines started more than 50 fires across the city. One of the best known, the “ham and eggs fire”, began when a woman cooked breakfast on a stove with a damaged chimney.

The earthquake had broken the city’s water mains, leaving firefighters with little water. The fire chief, Dennis T. Sullivan, was mortally injured when part of a building fell through his quarters; he died days later. Without him, the fire department struggled to coordinate its efforts.

Army troops from the Presidio and Fort Mason, under Brigadier General Frederick Funston, entered the city. They and the fire department tried to create firebreaks by blowing up buildings with dynamite and other explosives. Inexperience and the use of unsuitable black powder often started new fires rather than stopping them.

The fires burned for three days. They were finally stopped on 21 April, helped by a firebreak along the broad Van Ness Avenue, where mansions were dynamited, and by a change in the wind. By then the fire had consumed around 490 city blocks, about 4.7 square miles (12 km²), including the business district, Chinatown, Nob Hill and much of the South of Market area.

Order, martial law and relief

Mayor Eugene Schmitz issued a proclamation on 18 April authorising soldiers and police to shoot looters on sight. Although martial law was never formally declared, troops patrolled the streets and a number of people were shot, some of whom may have been innocent.

Between 225,000 and 300,000 people, more than half the population, were left homeless. Many fled across the bay to Oakland and Berkeley, while others lived in tent camps in Golden Gate Park, the Presidio and other open spaces. Relief came from across the United States and abroad, organised by the army and the American Red Cross. Thousands of small wooden “earthquake shacks” were built as temporary housing, and some survive today.

Key people

Eugene Schmitz was the mayor. His firm response in the crisis was praised, but he was convicted of extortion in 1907, a verdict overturned on appeal, as part of investigations into the city’s corrupt government.

Frederick Funston, acting commander of the army’s Pacific Division, sent troops into the city without waiting for orders. His decision was later criticised as well as praised.

Dennis T. Sullivan, chief of the fire department, had warned for years about the city’s water supply. His death removed the person best placed to fight the fires.

Andrew Lawson, a geology professor at the University of California, led the State Earthquake Investigation Commission. Its 1908 report, often called the Lawson Report, mapped the fault rupture in detail.

Harry Fielding Reid, a geophysicist, used the commission’s data to develop the elastic rebound theory of earthquakes, published in 1910.

The death toll

Contemporary officials reported 375 to about 500 deaths. City and business leaders had an interest in playing down the scale of the disaster to protect investment and insurance claims, and many deaths among the poor and in Chinatown were never counted.

From the 1960s onwards, San Francisco’s city archivist Gladys Hansen spent decades identifying victims from records and family accounts. Her work suggests that at least 3,000 people died, and some estimates are higher. The figure of 3,000 or more is now widely accepted, making the event one of the deadliest natural disasters in American history.

Rebuilding

San Francisco rebuilt quickly. Much of the city was reconstructed within a few years, though proposals by planner Daniel Burnham for grand new boulevards were largely set aside in the rush. Insurance payouts, totalling around $235 million, provided much of the capital, though some insurers went bankrupt or refused to pay.

Estimates of total losses at the time range from about $400 million to $500 million in 1906 dollars. Amadeo Giannini of the small Bank of Italy, who had saved his bank’s money from the fire, made loans to residents and businesses to rebuild; his bank later became the Bank of America.

The rebuilt city celebrated its recovery with the Panama-Pacific International Exposition of 1915. A proposal to move Chinatown away from the city centre failed after Chinese merchants and the Chinese government opposed it, and the district was rebuilt in its old location.

The fire also had a lasting effect on immigration. Because city birth and immigration records were destroyed, many Chinese residents were able to claim that they had been born in San Francisco and were therefore American citizens. They could then sponsor relatives from China, often called “paper sons”, at a time when the Chinese Exclusion Act barred most Chinese immigration.

Reconstruction brought political change as well. Investigations into bribery in city government, already under way before the earthquake, gathered pace during rebuilding and led to the prosecution of Abraham Ruef, the political boss who controlled Mayor Schmitz’s administration. Ruef was convicted and imprisoned, and the graft trials reshaped San Francisco politics in the following years.

Myths and facts

Myth: The earthquake destroyed San Francisco. The shaking caused serious damage, but most of the destruction was caused by the fires that followed.

Myth: Around 500 people died. This was the official figure at the time, but modern research indicates that the toll was at least six times higher.

Myth: The ground opened and swallowed people. Fissures and ground cracks did appear, especially on filled land, but accounts of large chasms swallowing people are not supported by evidence.

By the numbers

Timeline

• 1906, 18 April, 5:12 am: The earthquake strikes; fires break out across the city.
• 1906, 18 April: Troops enter the city; Mayor Schmitz issues his proclamation against looting.
• 1906, 19-20 April: The fire spreads through Nob Hill and other districts despite dynamiting.
• 1906, 21 April: The fires are brought under control along Van Ness Avenue.
• 1906, April: Governor George Pardee appoints the State Earthquake Investigation Commission under Andrew Lawson.
• 1908: The Lawson Report on the earthquake is published.
• 1910: Harry Fielding Reid publishes the elastic rebound theory.
• 1915: San Francisco hosts the Panama-Pacific International Exposition.

Legacy

The 1906 earthquake is the foundation of modern earthquake science in the United States. The Lawson Report and Reid’s elastic rebound theory remain central to understanding faults, and seismologists still use the 1906 records to assess risk in California.

The disaster also shaped building codes, fire safety and water supply planning. San Francisco built a separate high-pressure water system for firefighting. Later earthquakes, including the Loma Prieta earthquake of 1989, have been measured against 1906, and the event invites comparison with other city-destroying disasters such as the Lisbon earthquake of 1755 and the Great Kanto earthquake of 1923, where fire was likewise the main killer.

Why it matters

The 1906 San Francisco earthquake and fire destroyed one of America’s great cities in three days and showed that fire could be deadlier than the shaking itself. Its study transformed geology and engineering, and its rebuilding demonstrated the resilience of a modern city.