I was asleep on about the 20th floor of a hotel in LA in 1992 when the 7.3 Landers and 6.5 Big Bear earthquakes hit [0]. The building (which I believe was on rollers) was rocking quite noticeably.

I wasn't afraid for myself, though by the large, low-frequency motion I could tell it was a very large earthquake whose epicenter was a good distance away. I hoped it hadn't just taken out San Diego.

Though I'll admit, to go back to sleep and then be wakened by a second large quake (Big Bear hit about 3 hours later; it is considered a separate quake rather than an aftershock) was starting to get a bit freaky.

[0] https://en.wikipedia.org/wiki/1992_Landers_earthquake

[1] https://en.wikipedia.org/wiki/1992_Big_Bear_earthquake

I can't even imagine.

My daughter was born the day a 4.0 quake hit Piedmont, CA. I was in the fourth floor of a hospital in SF. The hospital beds were rolling around and I could feel the building moving. Very humbling for a guy from Minnesota who had only experienced minor quakes that didn't do much more than make it feel like a semi-truck was passing by outside. I don't know how I looked, but the mother of my child looked over at me and was like, "that was nothing."

I was in the shower on the second floor of a house in Orange County during the second quake. That was a wild ride.

A building can have a tuned mass damper[1] to help counteract the swaying. You can even turn that into a tourist attraction of sorts.[2]

[1] https://en.wikipedia.org/wiki/Tuned_mass_damper [2] https://www.youtube.com/watch?v=ohKqE_mwMmo

Taipei 101 even turned it into a mascot of sorts, the Damper Baby

http://www.alamy.com/stock-photo-damper-baby-and-tuned-mass-...

http://josellesoh.deviantart.com/art/damper-baby-292759048

Holy crap you're not kidding! That's incredibly cool and terrifying at the same time! I wonder how this tower in SF compares and if it did meet seismic code, will the sinking and leaning eventually take it out of code?