American Airlines CRJ-700 collides with helicopter near Reagan National

I lived in a townhouse in Alexandria directly opposite a marina just south of the DCA airfield - I could see the river and the final DCA approach from my bedroom window. There's a unit of Coast Guard helicopters stationed there and they fly up and down the river. And they fly a version of the blackhawk there.

Sometimes you would see Army blackhawks but most commonly it was Coast Guard. My suspicion is that the helicopter, whichever agency it was, was not where it was supposed to be. The collision happened in the final approach to runway 33 - which is the slanted one that takes the smaller jets like the CRJ-700.

EDIT - Confirmed Army