Justin Wilson is in a coma following an accident at Pocono. A car in front had an accident and it seems Wilson was then hit on the head by a very heavy bit of debris from that other car's accident. The yellow car in the video is the first accident, Wilson is following about 10 cars behind. It looks like the nose cone was what hit him and knocked him out cold and he then steered into an infield wall.
Fingers crossed that he makes a good recovery.