Details are still coming together, and the immediacy of the crisis has not yet passed, but a horrible scene has unfolded in Washington, D.C.
A gunman armed with a rifle and perhaps a handgun opened fire Monday inside a building at the Washington Navy Yard -- killing at least four people and wounding at least six more, including a security guard and a city police officer, authorities said.SWAT officers swarmed the building, the headquarters of the Naval Sea Systems Command. The shooter was believed to be wounded, a source told NBC News, and crews were combing the facility to make sure there were no other gunmen.It was not clear whether the gunman was civilian or military.
I've seen some reports about the possibility of multiple shooters, but at this point, that remains unconfirmed.
For those unfamiliar with the D.C. area, the Navy Yard is about a mile and a half south of the U.S. Capitol, just east of where the Washington Nationals baseball team plays.
For those following the story through social media, NBC's Farra Kober has pulled together this twitter feed with updates.
Update: NBC News has confirmed that the Navy Yard shooter is dead.