"The Rose Canyon Fault Zone strikes through the heart of the San Diego metropolitan area, presenting a major seismic hazard to the San Diego region, one of the fastest growing population centers in California and home to over 3.3 million residents," they wrote in an executive summary. "The region’s large population coupled with the poor seismic resistance of its older buildings and infrastructure systems, make San Diego vulnerable to earthquakes."
Damage would extend along the fault from La Jolla, past the airport, through downtown, south of the bay and into Tijuana, Mexico.