In 1906, 90% of San Francisco's buildings were constructed with wood frames and only 54 of the city's buildings were fireproofed. These highly combustible buildings, which were not required to have sprinkler systems, were packed together on narrow streets. Frame buildings were constructed from wood, sometimes on stilts, with brick chimneys held together by lime mortar. The city required that the roofs of all buildings within the fire limit zone be covered with metal, slate, tiles, terra cotta, or asphalt; all buildings had to have fire escapes.
The fire department responded to 52 fire alarms in the first half-hour following the earthquake. Initial battles with fires in the Mission District and the Western Addition were successful. These victories were countered by the conflagration that grew up at the eastern end of Market Street (map), near the waterfront. This area of the city was built on made land, which meant it suffered more from the earthquake's shakings and thus saw more blazes erupt. Finding fire hydrants dry, firemen resorted to saloon watering troughs and the sewers to douse the fires. As morning dragged on, fires sprouted up in other areas of the city. These new fires were blamed on cooking stove fires that were connected to earthquake-damaged chimneys.
The immediate shock people felt at finding entire building fašades reduced to rubble was quickly overshadowed by the fires that engulfed San Francisco. By the end of the third day of the fires, many of the areas where these refugees stood would also be reduced to ashes.
As the fires rapidly spread and with little available water, the San Francisco Fire Department turned to dynamite. The intent was to demolish buildings to create firebreaks that would contain the flames. Unfortunately, the Presidio provided the wrong type of dynamite: highly flammable black gunpowder, which was not as effective as nitroglycerine, stick dynamite, or gun cotton. After the flames were extinguished, the explosives did nothing but create an avenue for the fires to spread during those first critical hours: Buildings and walls that might have served as firebreaks had been demolished.
The explosives also raised a dust that choked the lungs and impaired visibility. But perhaps the worst damage was the creation of even more fires as flaming debris ignited ruptured gas lines. Unwilling to admit responsibility for their collective mistakes, the Mayor, the Army, and the Fire Department all pointed fingers at each other, adding fuel to the administrative confusion that reigned during the fire.