The easiest way to figure out something like this is to look at the footage a frame at a time. This shot:
Has at least 2 layers. Always think of effects shots as layers. What do you need to cut out and arrange on the screen to pull off the effect.
If you wanted to use just two layers you would need one with the actors shot from above with the background removed (think keying or rotoscope), and one layer with a falling camera.
The falling camera background footage could also be recreated with 5 flat layers arranged in 3D space to form the buildings and the street. The building sides would be much taller than the comp and about as wide. You could parent all of the background layers to a 3D null and then animate the position of the null to get the feeling of falling or you could simply animate the position of the camera. It will be easiest to arrange the 3D layers in AE with the street on the XY plane and the buildings rotated in Y and X and then positioned to form kind of a tunnel. It's just easier to animate a camera moving forward than it is to make it point straight down and animate a fall. When you get the set built from your 3D layers you a couple of position keyframes will complete the move. Then a little color correction and possibly some lights and you're done.
This was a really informative and detailed answer and I thank you very much for taking the time to answer my query.