Both were on final approach, or so I've read. The things are pretty much experimental, so I'm figuring there aren't even that many around to ground.
On a side note, there was another Mitsubishi MU-2 crash yesterday as well. It is now up to 80 fatal accidents, or one fatal accident for every ten planes in the MU-2 fleet world wide. The FAA has done three investigations, and declared it safe, and although they have suggested special type training, they've stopped short of requiring a type rating.