My drivers window in 2002 impala fell when I shut the door. How do I fix it?

The window fell of the track inside the door, you usually have to remove the door panel and re-seat the window on the tracks.

since you have electric windows,their is NO track.it is held on by 2 plastic hengis,the whole assembly will have to be replaced,it works off of cables,remove the door panel and you will see and probly find the hinges at the bottom of the door.

Same thing happened to me with my grand prix... actually did it on 3 of the 4 doors during the time I owned it. The window regulator is poorly designed in these cars.. square plastic pegs in a glass window and a metal cable are not an ideal mix. You most likely need to replace the regulator.. Take the door panel off and inspect the window and the regulator. Inspect the clips. I am sure one has broken.

I have an 08 impala and same thing happened. I had to replace the window regulator assembly. Its all one unit. Eady fix. Seems to happen in the worst time tho.