American Airlines CRJ-700 collides with helicopter near Reagan National

Yeah, I believe that's the Potomac Yard area you're describing.
Could be. I got the map up and see nothing labeled Potomac Yard but I am really bad at visualizing stuff like this (esp. in DC where I notoriously get lost every time I've ever driven there).

The video I have seen is from different locations - and I'm sure there are many cameras in that general area. If you can see the river and the activity is behind it, that's going to be from the DC or Maryland side. If the river is on the other side of the activity, it's taken from VA.
Only thing I can recognize what I'm looking at is a lit up Lincoln Memorial which, as I said, is not really a help for me. But it looks like that helicopter was traveling fast.