Shaking all over ... the Pacific coast

[classicdrogn]

As a kid in New Hampshire, I was very disappointed to wake up after having fallen asleep on the couch one day to discover I'd missed an earthquake. Still living in the northeast, the only time I've noticed the floor shaking is when I'm inside a particular building and lots of people are walking around... I'm not sure why this happens, but it's a six-floor steel frame and concrete industrial type thing, so lightweight construction isn't it.