considering where the airport is located in relation to the scene, it's not difficult to keep that airspace clear anyway. I've been keeping my eye on it for hours and it looks like pretty normal activity to me. There are a few planes that are on the ground but that's also fairly normal, as they have their transponders on while taxiing. (that's an oddly spelled word).
But also considering the situation, I'm not surprised in the slightest.
However, wasn't there at least 1 news chopper there after it happened? And there was plenty of amateur drone footage as well. As long as those are kept under a certain altitude, are they under radar?