The largest dollar fire loss in United States history occurred in the East Bay Hills, within the California cities of Oakland and Berkeley, between October 19 and 22, 1991.  Twenty-five lives were lost and more than 3,000 structures were destroyed by a wildland-urban interface fire in one of the most heavily populated metropolitan areas of the North American continent.  The fire completely overwhelmed the firefighting forces of the area, consuming everything in its path, and was only stopped when the Diablo wind conditions abated.  The wind had threatened to drive the fire across the entire city of Oakland.

The factors that set the stage for this disaster were identified long before the fire occurred, and the potential consequences had been predicted by fire officials.  Nevertheless, their warnings went unheeded, and the measures that could have reduced the risks were not implemented.  More than one billion dollars in damage resulted from a fire that exceeded the worst expectations in the most concerned fire professionals.  It was a fire that demonstrates how natural forces may be beyond the control of human intervention and should cause a renewed look at the risk of wildland-urban interface fire disasters.

Large areas of California are known to be critically vulnerable to wildland-urban interface fires due to the development of urban areas in locations that are subject to extreme fire hazards created by climate, terrain, and natural fuels.  Several major fires have occurred over the years, including one in 1970 that involved a large portion of the area burned in this incident.  The coastal region was particularly vulnerable in the fall of 1991, after five years of drought, several months with no recorded precipitation, and reduced efforts to control wildland interface hazards due to State and local budget limitations.  The key ingredient in this incident was the Diablo wind condition, which combined with the other critical fire risk factors to create an irresistible destructive force.