It's a bit disconcerting when the office is shaking. It would be one thing if I worked in The Los Angeles Office of The Corporation, but I'm don't—I work in The Ft. Lauderdale (as in Florida) Office of The Corporation (and besides, we don't have an office in Los Angeles).
I'm not alone in this—I asked around and yes, other people felt it too. It wasn't a violent “up and down and oh my God we're all going to die!” type of shaking, more of a “I can just make out this vibration in the floor; the building isn't going to collapse on us, is it?” type of vibration.
The only consolation (and it's not much) is that this isn't the first time this has happened.
And no one can explain why …
My friend and fellow cow-orker B mentioned on GoogleMyFacePlusSpaceBook that the shaking was caused by frieght trains going by. It makes sense, seeing how there's a railroad right next to the building.