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At least one gunman opens fire at Washington, D.C.'s Naval Yard; the city's mayor said at least 13 have been killed. One of the gunmen is dead, while the police chief states that another suspect is at large. (NBC)(The Washington Post)(CNN)
A man is in custody, arrested by uniformed U.S. Secret Service Police on Pennsylvania Avenue adjoining the White House's North Lawn, after loud popping noises were reported, having thrown fireworks over a fence there (the area is off-limits to all traffic); he was not judged to be a threat but the incident came right after the mass shooting nearby. (NBC)