[TheZMan]

You got it: http://en.wikipedia.org/wiki/1989_Loma_Prieta_earthquake

Seems the number has been adjusted over time; I thought it was a 7.6 or 8.6, certainly not a 6.9.

[EDINVA]

Yeah, I seem to remember at the time they were talking in the 7s. I don’t think that from my own sense of being caught in today’s quake I’d have given it as high as a 5.8, except on my nerves scale. It took my “brain” 28 of the 30 seconds to even realize it WAS a quake.