According to the USGS, a small, 2.8 magnitude aftershock occurred at 2:46 p.m. near the epicenter of the original 5.8 magnitude earthquake. On the bright side, the USGS reports that “the population in [the D.C.] region resides in structures that are resistant to earthquake shaking, though some vulnerable structures exist.” The USGS has issued a preliminary report that as many as 9,627,000 people may have been affected by the quake which was felt up and down the East Coast this afternoon.