Head of the USGS (United States Geological Survey), Marcia McNutt, is quoted as warning that the shaking may not be over in Virginia. She said "What the concern is, of course, is that this is a foreshock. If it's a foreshock, then the worst is yet to come." The magnitude 5.9 Virginia earthquake is probably plenty enough already for those who evacuated the White House, Pentagon, and the Capitol.