Updated at the bottom: Caltech downgrades the quake. Also, comments from L.A.'s own Caltech experts go national. First posted at 11:10 a.m.
Stranger things have happened? We don't think so. A California-sized earthquake hit the Washington, D.C. area this morning, leaving residents positively bewildered.
What was that? It was a 5.9 shaker centered four miles southeast of Louisa, Virginia, [added]: four miles southwest of Mineral, Virginia, and about 83 miles southwest of Washington, D.C., according to the USGS. It struck at 1:51 p.m.
It was felt from North Carolina to Boston according to reports. And ...
... the Pentagon was reportedly being evacuated as a precaution.
Injuries? We don't know. But even by L.A. terms 5.9 is a rocker.
Added: Some folks in New York, where the tenth anniversary of 9/11 is going to be a very big deal, were caught off guard and, frankly, a little bit scared that this might have been something other than a temblor, CNN reported.
CNN's Pentagon reporter said one could feel "the whole Pentagon was moving underneath you."
The building suffered some kind of flooding and was thus evacuated but CNN reports things were under control shortly before noon West Coast time.
More: CNN reports that the Washington Monument, the Lincoln Memorial and the entire National Mall were evacuated at as a precaution.
A nuclear power plant not far from the epicenter lost its power but was able to get back up via diesel generators. An "unusual event" was declared. More.
Update: Caltech earthquake experts in Pasadena went national during a press conference early this afternoon.
Caltech seismologist Kate Hutton said aftershocks in the "2s and 3s" were possible today.
Lucy Jones of Caltech said "chances are the worst has already happened."
She wasn't surprised by this shaker, either:
"It is an area that's had earthquakes in the past," she said. "This is a recognized seismic zone. There was a 3.9 in 2003 followed a few months later by a 4.5 in the same general area."
Jones, however, said this was the largest quake in the region since 1897, when a 5.9 also struck Virginia.
The experts expressed some concerns for brick buildings in the area, which are more common than in California, where such structures have been banned since 1935.
But ... this quake struck in a very rural area: The nearest bigger town is 20 miles away, the experts said.
Jones said this quake was felt from Boston to Ohio to Georgia.
Update No. 2: The USGS this afternoon downgraded the quake from 5.9 to 5.8.
Added: The Washington Post tweets that planes bound for New York and Philadelphia are being held back.
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CNN reports that President Obama will have something to say about the shaker shortly.
More: Advisers today told Obama that there was no major structural damage as a result of the temblor, according to an Associated Press tweet.