The same plane crash which changed the way that people would view flight as a method of travel forever is also plaguing your mind with unnecessarily violent dreams. You are preoccupied thinking about these reports of damages to the world trade center and seeing other images of plane crashes in the media. With your mind being so over stimulated in this regard and entirely oversaturated with the same reports, it is not hard to understand why it would be focused on this kind of thing.
The content of a dream is heavily based on what is familiar. Whatever you have been thinking about recently, consciously or subconsciously, will make its way into your dreams somehow, in the form of a symbol or as a physical object. In your case, the plane crash might not represent anything outside of itself. You may just be dreaming about it because plane crashes or air travel disasters have been on your mind recently.
In fact, you are even more prone to dream about a plane crash if you happen to be going on a trip by way of plane soon. Many people, no matter how comfortable they are with flying, cannot manage to shake a small, imperceptible fear at the back of their mind that makes them scared of being in aircrafts. Even if you are highly comfortable and have been on a plane hundreds of times, you can hardly help but have small fears that are mostly brought on by the fact that you are going to be taking a plane soon. Your fears will be far more magnified and real though if you are an infrequent flier and even worse if you are a first timer. Try not to let the fears get to you. It is a tired and overused fact, but it may make you feel better to be reminded that the chances of you dying in a plane crash are much less than the chances of you dying in a car crash on a trip on the road. Trust your pilot and know he is going to do everything he can to get you home safe.
Dreaming of a plane crash can also be a symbol for a total halt of progress, especially when you are the one on the plane. You have been cruising along just fine in your world, but something has just come along that totally changed your progress and set you to the ground against your will. It will take some time to recover but you will be able to get back on your feet and back onto a good track for fast travel soon enough.