Almost 20 years ago now I was present at a briefing given to public officials in San Bernardino and Riverside regarding the expected effect of a major San Andreas quake upon the Inland Empire. Movement along the fault will be about ten feet up and twenty feet north. Every road, railroad, and utility will be severed.
That’s in addition to the damage done to homes, businesses, freeway, etc. It’ll be a mess, but the older I get the less likely it seems it will be that it will happen in my lifetime.
There are fears a very large magnitude quake on the San Andres could trigger the Newport/Inglewood fault and others. The LA area is riddled with big cracks or faults. The San Andres goes right up the Cajon Pass and up behind Wrightwood heading north towards San Francisco and South towards Palm Springs, Imperial Valley etc. The inland “crime” empire will be toast.