When I came back upstairs they were arguing if it was just someone heavy coming up the stairs or if the office was shaking from something else. I didn't feel anything, so I suggested it was a train going by. The tracks are close enough that a good, fast train and get my desk rattling pretty good.
They conceded it might be a train, but kept going on about how it would have to be an awfully long train since they were still feeling it.
At that moment - BOOM - we heard that thing before all the walls started to shake and the file cabinets tried to do the hop.
"Okay, THAT's an earthquake." We pipped up helpfully. I added that, at that exact moment, Facebook and Twitter were definitely lighting up with 'Holy Crap!! Earthquake!!"
5.3 according to ADN, Facebooks folks are reporting it was larger. I think this is the biggest one I have felt.