Although the exact cause was never determined, the fire began in the undeveloped chaparral and grasslands of Wildcat Canyon, just east of the ridgeline of the Berkeley Hills, and was propelled over the ridge and southwestward just south of Codornices Creek by a strong, gusty, and intensely dry northeasterly wind.

A number of UC students fought the advance of the fire as it approached the north edge of the University of California campus, at Hearst Avenue.

Firefighters were rushed in from neighboring Oakland, and San Francisco sent firefighters by ferry across the bay.Firefighting efforts were hampered by the inadequacy of water mains in northern Berkeley, where rapid development after the 1906 San Francisco earthquake had outgrown the water supply in the fire area.

The fire was halted only when the northeasterly winds died down and were replaced by the cool, humid afternoon sea breeze.

at 3000 Shasta Road,[3] on the interface between the residential area and Tilden Regional Park, very close to the putative origin of the 1923 fire.