Yes, they can happen almost anywhere.....
http://earthquake.usgs.gov/earthquakes/recenteqsus/Maps/US2/38.40.-78.-76.php
Earthquake Details
* This event has been reviewed by a seismologist.
Magnitude 3.6
Date-Time
* Friday, July 16, 2010 at 09:04:47 UTC
* Friday, July 16, 2010 at 05:04:47 AM at epicenter
Location 39.167°N, 77.252°W
Depth 5 km (3.1 miles) set by location program
Region POTOMAC-SHENANDOAH REGION
Distances 15 km (10 miles) NW of Rockville, Maryland
30 km (15 miles) ENE of Leesburg, Virginia
35 km (20 miles) NW of WASHINGTON, D.C.
70 km (45 miles) WNW of ANNAPOLIS, Maryland
Location Uncertainty horizontal +/- 13.3 km (8.3 miles); depth fixed by location program
Parameters NST= 15, Nph= 15, Dmin=44.7 km, Rmss=1.49 sec, Gp=133°,
M-type=Nuttli surface wave magnitude (mbLg), Version=6
Source
* USGS NEIC (WDCS-D)
Event ID us2010yua6
http://earthquake.usgs.gov/earthquakes/recenteqsus/Maps/US2/38.40.-78.-76.php