earthquake?

our building shakes pretty frequently and at first i would have that native californian knee-jerk reaction of wanting to duck and cover every time i felt a tremor.  over the past few weeks i've grown accustomed to the shaking and told myself there are no earthquakes in chicago.

well, right when i was getting over stressing every time our building shook (like 5 times a day), will tells me that once in awhile there are earthquakes in chicago.  

just great.