on firm ground. Montgomery Street, often called the financial center of the West, roughly follows the original shoreline of San Francisco Bay, which ran close to the base of Nob Hill. The six blocks from here to the current waterfront are all “made” ground, land literally manufactured by filling the bay with sand, garbage, rotting trees, and other detritus. Scores of abandoned wooden ships were scuttled and lie beneath this section of San Francisco. Made ground is loose and unstable. It takes on the character of a liquid when shaken, such as during an earthquake. Imagine standing on a pile of loose sand. Shuffle your feet back and forth quickly. They sink into the sand. The same thing happens when the ground shakes around a building that is not set on firm ground.

Most of the destruction and the five deaths in San Francisco caused by an 1868 earthquake, which originated across the bay in Hayward, happened here. Extensive damage also occurred here in 1906, as well as in other areas of the city built over made ground. The City Hall, then at the corner of McAllister and Larkin Streets, had been built on shaky underpinnings—the site of the city’s first cemetery. The 1906 City Hall was the grandest and largest municipal building on the West Coast. It took more than 20 years to build and only two minutes to collapse. Today the main branch of San Francisco’s library occupies the site, housed in a six-story building that looks more like a bunker than a municipal ornament. Its inside is braced with steel rods and girders, some set at inconvenient angles. At the main entrance, inside a glass case, are artifacts, including bottles, broken chinaware, and a wedding ring.

For 30 years, I have walked the streets of San Francisco, taking photographs. My goal is to document the city before the next major earthquake. I have often wondered how San Francisco will look after that. Which buildings will fall and which will still be standing?

I worked for the U.S. Geological Survey for 16 years, studying earthquakes, so I know what they can do. I admit that I feel queasy whenever I drive into an underground garage and park my car. I walk quickly to the nearest elevator, aware that even after I reach it and step inside, I have few options should the ground start to shake. Yet I have a fascination with earthquakes and hope to be in San Francisco for the next big one. I do not wish destruction on the city—it remains my favorite city in the world—but I know that earthquakes are inevitable. As are fires. Still, a question goes through my mind: Have architects and structural engineers finally succeeded in securing San Francisco? The city leaders of 1906 were convinced they had.

San Francisco burned six times between 1849 and 1851. It was damaged by earthquakes in 1865 and 1868.

Those disasters led to the creation of an effective fire department and to the establishment of a fire limit, in the downtown area, where only brick and steel construction was permitted. Many of the buildings in the fire limit collapsed in 1906, and the entire area burned in 24 hours.

The closest thing to a “ground zero” in 1906 was Lotta’s Fountain at the intersection of Kearny and Market Streets, still one of the busiest corners in the city. Here, after the fire had cooled, bulletin boards were erected for people to put up notes, asking about loved ones or looking for work. Lotta’s Fountain is still the gathering place for the anniversary of the earthquake. Last year, at 5:12 a.m., the time it struck, six survivors were honored by a crowd of a thousand and by the mayor, who laid a wreath on the fountain. Today, about a hundred people who were in the city at the time of the earthquake are still living in San Francisco.

Almost everything that would have been visible from this spot in 1906 was destroyed. Just a few buildings along Market Street that predate the earthquake are left.

At the east end is the Ferry Building. Built of brick, the building was seriously damaged by the earthquake, but it stood. Then the fire approached. Only the heroic efforts of the U.S. Navy, using fireboats, saved the building. At times the firefighters had to turn their hoses on their own ships to put out fires started by falling embers. Afterward the U.S. Army Corps of Engineers announced that the building would be razed, but, fortunately, that didn’t happen. Instead, it was refurbished and strengthened and appears today much as it did in 1906.

A few blocks west, across Market Street from Lotta’s Fountain, is a narrow structure called Central Tower. Known in 1906 as the Call Building—named for the newspaper published there—it was the tallest building west of the Mississippi, rising 16 floors. Today it is easily missed. Its distinctive domed roof, which capped a restaurant in 1906, is now long vanished. The Call Building survived the earthquake because it had a steel frame, but the interior was gutted when fire, entering through an underground tunnel, was sucked up the elevator shaft. The building was remodeled extensively in 1938.

Another survivor is the James Flood Building, next to the cable-car turnaround at the corner of Powell and Market. The largest building in San Francisco at the time of the earthquake, the exterior looks essentially as it did when the building opened in 1904. It was almost untouched by the earthquake, which proves buildings can be constructed to withstand violent shaking. For a time it seemed that its modern fireproof measures would save it from the flames, but eventually they caught hold. It was one of the last buildings to burn along Market Street.

Chinatown also burned that first day. By the next morning, the fire had topped Nob Hill and destroyed the interior of the Fairmont Hotel, then under

construction. By the second day, it approached Van Ness Avenue. Firefighters decided to make their last stand there.

The military had been using dynamite and black powder to demolish rows and rows of buildings, hoping to make firebreaks and halt the advancing blaze, but without success. Now, along Van Ness, the widest street in the city, the Army was given permission to destroy a long row of Victorian mansions. They assembled a line of field artillery and readied their demolition experts.

At 5:00 p.m. on the second day of the fire, the command was given. A barrage of artillery shells and systematic dynamiting leveled three blocks of homes in 20 minutes. Then, unable to watch the willful destruction of his city, Mayor Eugene Schmitz ordered the demolition stopped. A hose line was pulled from the bay along Van Ness for more than a mile (all the hydrants in the city were dry, the mains that fed them having ruptured), and three steam pumps relayed the water. The next 24 hours saw a frantic fight to save what remained of San Francisco. When flames began to jump Van Ness, people on rooftops across the street pulled out burning shingles with their bare hands.

A century later, a debate continues over whether it was the demolition or the firefighting or a shift in the wind that stopped the fire at Van Ness. Nevertheless, the avenue marks a boundary today. To the east is the rebuilt city. To the west are older sections, where Victorian houses line the streets, a reminder of the time before the earthquake and fire.

As soon as the embers cooled, San Francisco was faced with the challenge to rebuild, and, to do that, it needed its people.

In rough numbers, of the nearly half-million citizens living in the city in 1906, about 150,000 sought refuge across the bay and 50,000 headed south along the peninsula. That left nearly 300,000, the vast majority of them homeless.

The Army constructed tent camps at the Presidio and Golden Gate Park, and wooden barracks were built, each one divided into sixteen apartments. These were temporary accommodations that would suffice during spring and summer months. The approaching winter demanded more protection. But then the city inaugurated a new plan, one that would allow many families to own their first homes.

More than 5000 “earthquake cottages” —small two- and three-room houses—were constructed of pine floors, redwood walls, and cedar roofs. A cottage rented for two dollars a month, and the money was applied to the purchase of the building if the new owner later moved it to a private lot.

Today, less than two dozen earthquake cottages survive. Many have been altered, in use as garages and storage sheds, and are barely recognizable. Two of them, recently restored to their original conditions, including the color of the paint, which was described in 1906 as “bench-park green,” are on the grounds of the Presidio, behind

the Old Post Hospital. The low ceilings and small rooms are surprising, but for people who had been homeless for months and facing winter, they were a very welcome retreat.

Thousands of men were hired to clear the streets of rubble. Train tracks were laid along Market Street and other major thoroughfares to hasten the process; much of the debris went into the filling of a marsh on the north side of the city.

In 1915, San Francisco invited the world to visit the Panama-Pacific International Exposition, which was built on new land. Officially, the exposition was to celebrate the opening of the Panama Canal, but San Franciscans knew this was a good opportunity to showcase their rebuilt city. Nineteen million people came. They strolled through magnificent gardens and huge, temporary buildings that housed the exhibitions. Afterward the buildings were razed, the area was subdivided, and the lots were sold, creating the large residential area known as the Marina district.

On October 17, 1989, the largest earthquake since 1906 rocked San Francisco. A section of the Bay Bridge broke. A tiered freeway in Oakland collapsed. In San Francisco the greatest destruction was in the Marina district, the newest-made ground in the city.