A city prized for it's mild climate and beaches, San Diego will find this proximity to the Pacific its doom. Without mountains as a solid backdrop, waves will wash in and out, over San Diego, as though it were a beach. This will scour the city clean, dragging most of it out to sea and depositing the rest inland as flotsam. Those seeking San Diego after the shift will be shocked to find it apparently missing. And the remnants will in any case go under water within two years, due to polar melting.
Note West Coast Volcanoes commentary.