A rare natural disaster jolted the Mid-Atlantic region of the East Coast on Thursday evening, prompting some to flee offices and homes, but causing no serious damage or injuries.
On Twitter, the hashtag #earthquake was trending.
There have been no immediate reports of damage or injury.
Emergency management officials received a lot of calls in the aftermath of the tremors, Pagliughi said.
Among the areas that reported shaking on Thursday included New York City, Philadelphia, Baltimore and Washington DC.
Thursday's quake marks the first time the region was hit by a minor quake since a stronger 5.8 magnitude quake struck on August 23, 2011.
ABC News: Preliminary 5.1 earthquake hits Dover
DE 105.9's Rob Petree hit the streets of Dover for reaction from residents on what they experienced during the quake, which one man said was deafening.
The station also writes that Paul Caruso, a geophysicist with the USGS, says there is potential for aftershocks.
"I was talking with the other seismologists and we said, 'Wow, we don't ever remember a quake in DE", he said.
Others commented that they had not felt a thing.
Fill out the form and tell us where you were and if you felt anything.
Brian Casey, an attorney based in Lake Success, said he felt the temblor in his office building between Marcus Avenue and Union Turnpike shortly before 5 p.m. She said there were no signs of damage at the base nor would there be any change in its operation. It caused damage to public buildings, pipes and monuments, most notably the National Cathedral and the Washington Monument.