[RightWhale]

what if that was just a pre-shock?

Not likely. The first one is the main event, then come aftershocks of lesser magnitude.

[Alia]

Reading all the comments from locals in the LA basin and parts thereof: Sending you wishes for cool nerves; and no damage.

Quakes were "interesting". It was the aftershocks which could drive me batty; especially if they were clustered. Praying it was a release of seismic tension.