Image from the USGS via the National Geophysical Data Center.
Do you remember the 1971 San Fernando Valley Earthquake? It was the big 6.6 quake that devastated the northern part of the Valley. It was so big it brought Governor Regan and Vice President Spiro Agnew to Los Angeles, declaring it a national disaster area.
This is a long video that captures the people, the era, and the tragedy that lived through the 1971 quake. having lived through a few quakes here in the SFV, I think its safe to say that for those still in residence here, we remember the devastating potential from below the earth.