Note that this quake was not on the San Andreas - it was in the Eastern California Shear Zone, a separate fault system near Death Valley. The epicenter was about 125 miles away from LA, and almost closer to Las Vegas (which also felt this quake). The limited damage was largely because it was far away from any populated areas - the nearest cities are Ridgecrest (pop 27,000) and Trona (pop < 2000).