With the country’s highest per-capita murder rate and more saloons than grocery stores, San Francisco at the turn of the 20th century was no place for the faint of heart. Yet people flocked there anyway, drawn by the Mediterranean climate, ample employment opportunities and burgeoning cultural scene. Its roughly 400,000 residents prided themselves on living in the largest city west of St. Louis and the busiest port on the U.S. Pacific coast. Opulent hotels and high-rise office buildings, such as the 18-story Call Building on Market Street (then the tallest building in California), dotted the thriving downtown business district, and a state-of-the art City Hall had recently finished construction. San Francisco had even begun attracting top-flight entertainers from around the world. On April 17, 1906, for example, legendary Italian tenor Enrico Caruso sang in a production of “Carmen” at the Grand Opera House.

The next morning, however, San Franciscans’ lives were suddenly ripped apart. At 5:12 a.m., a foreshock jolted residents out of bed and was immediately followed by tremors so powerful they were felt as far north as Oregon, as far south as Los Angeles and as far inland as central Nevada. Experts later estimated the quake’s magnitude at a whopping 8.3 on the Richter scale (or 7.9 on the more accurate moment magnitude scale). As the ground shook, water and gas mains ruptured, telephone and telegraph communication ceased, and a spooked herd of cattle stampeded through the streets. Steel-framed buildings held up fairly well. But the vast majority of the city’s structures had been built with wood or brick, and these broke apart with frightening ease, particularly in low-lying coastal areas. Even City Hall’s majestic bronze dome came crashing down. “The noise and the dust, and the feeling of destruction, all combined to daze a man,” a policeman later recalled. “All about us houses were tumbling, and falling walls and chimneys and cornices were crushing men and horses in the street.” Meanwhile, elsewhere in California, Santa Rosa’s downtown and Stanford University both suffered near-complete decimation, a train tipped over in Point Reyes, a lighthouse in Point Arena was damaged beyond repair and more than 100 patients died when an insane asylum collapsed near San Jose.

The earthquake, unfortunately, was only the beginning. Toppled wood and coal stoves, as well as broken gas lines and chimneys, precipitated fires all over San Francisco. At around 10:30 a.m., for instance, a woman on Hayes Street tried to cook breakfast, not realizing her flue had been incapacitated. Her wall quickly ignited, and the flames then spread to other buildings. Eventually, this so-called ham-and-eggs fire would burn up what was left of City Hall, including most of the city’s records and tens of thousands of books, along with a large arena that had been turned into a makeshift hospital. Various fires, some set by arsonists hoping to collect insurance money, consumed newspaper row, the Grand Opera House and nearly all of San Francisco’s libraries, hotels, banks, religious institutions, art galleries and department stores. Most residential neighborhoods also went up in smoke, from the mansions on Nob Hill to the tenements south of Market Street. Firefighters jumped into action, but broken water pipes largely prevented them from using their hoses. Instead, they tried to create firewalls by demolishing houses with dynamite, a strategy that ended up sparking more new blazes than it prevented. To make matters worse, San Francisco’s fire chief, whose previous requests to improve the city’s firefighting capabilities had been ignored, was mortally wounded in the earthquake, leaving the department leaderless.

San Francisco Mayor Eugene Schmitz, a former musician who would soon be indicted on corruption charges, only added to the chaos by proclaiming that all looters would be shot on sight. Before long, newly arrived federal troops had put the city on a lockdown akin to martial law. Reports of their behavior vary. Though many soldiers helped admirably with relief and firefighting efforts, others purportedly went on a killing spree, fueled in part by liquor stolen from saloons they were supposed to be shutting down. Their alleged victims included a Red Cross official, an old woman who refused to turn off a lamp and a deaf fireman who inadvertently disobeyed a command. Despite their orders, the soldiers moreover turned a blind eye to looting in Chinatown—and at times participated in the looting themselves—prompting the Chinese consul general in San Francisco to complain that “the National Guard was stripping everything of value.”

All told, the earthquake and fires destroyed more than 28,000 buildings and left over half the city’s population homeless. “Not in history has a modern imperial city been so completely destroyed,” author Jack London wrote in the catastrophe’s aftermath. “San Francisco is gone. Nothing remains of it but memories and a fringe of dwelling houses on its outskirts. Its industrial section is wiped out. Its business section is wiped out. Its social and residential section is wiped out.” Officials originally put the death toll at 498 (plus 166 more outside the city). But researchers later concluded that at least 3,000 people had died. Among U.S. natural disasters, only the 1900 Galveston, Texas, hurricane—and possibly the 1928 Okeechobee hurricane in Florida—are believed to have claimed more fatalities. Ever since the 1906 quake, fear of another “Big One” has been a fact of life for those inhabiting the Bay Area.