Can a plague of locusts be far behind?

Here at DeLorenzo's Dugout, we experienced today's earthquake first as a shaking of my desk while I was working on my laptop. At first I thought it was our cat bumping up against the deskleg, but I couldn't see him anywhere (a 20 pound cat is hard to miss). Then I heard my bobble-head dolls on the wall-length bookcases shaking. I got up and walked over to the bookcases and saw them moving towards me, so I grabbed on to them to make sure they didn't fall over (a full room of books falling on you isn't something I need right now). After the shaking stopped, about 45 seconds later, I looked around to see what was going on, went over to the window in my home office, opened it, and saw some of my neighbors on their balconies looking at me. All of us thought a truck had hit the building or something like that, but we quickly realized that it wasn't anything like that. Naturally my first instinct was to call my wife at work across town on my cell phone -- we all know that don't work no more. I've been in LA & SF for small earthquakes in the past but this was truly scary. I am more freaked out than our cat! Hard to believe Philadelphia and this area would be hit with an earthquake like this. My sympathies to anyone injured or otherwise impacted by this. Now everyone is driving out of the city -- reminds me of what Center City was like in September 2001 -- hopefully this is truly an "isolated incident."