Pictures and videos:
TRACTOR TRAILERS FLY IN DALLAS

Here is a video -- you have to sit through a lengthy commercial for an exciting movie Battleship, but worth it to see the video -- stay with it, better view near end of clip. (Though I just looked again, and different commercial, and there is a button to skip the commercial):
http://www.youtube.com/watch?v=LN5Izcf-z9k

Some pictures, story, etc.:
http://dfw.cbslocal.com/2012/04/03/tornado-reports-coming-in-from-across-north-texas/

Robert