How long ago was that? I felt one from Michigan myself a few years back, that originated down in southern Indiana. That was around 3 or 4AM, though, so unless you were working late or living in your office...

The American midwest may not be earthquake central, but it has its faults. New Madrid, in particular:

http://en.wikipedia.org/wiki/New_Madrid_Seismic_Zone

I remember the noise around Iben Browning's 1989/90 prediction, but it looks like nothing major has happened there since. Yet.