If you felt the earthquake this afternoon (I’m at my office downtown right now), please go to the USGS website and report if you felt it. The information people report to the USGS really helps the scientists in their work studying earthquakes: http://earthquake.usgs.gov/earthquakes/recenteqsus/
I did not notice anything at 20th and Union. Did anyone in the neighborhood feel it?
Also, if you felt, help scientists out by reporting it here: http://earthquake.usgs.gov/earthquakes/dyfi/events/us/c0005r