I was at work and it was interesting to watch everyone realize what was happening at the same time. I couldn't feel the earth tremble, I just felt the building sway from side to side. It's two hours later and I still have a funny feeling in my stomach.
Some people went home from work citing being too shaken up to continue, but I think it's just because it was so unnerving. It wasn't bad enough for anything to fall off my desk, for example.
So I don't think we were in any real danger, but it was definitely spooky!