[gshubert17]

I believe the source is Miasto Ruin or City of Ruins [1], which is a CG visualization based on computer modeling of what an airplane would have seen near the end of the war. See also IMDB [2].

[1] https://www.youtube.com/watch?v=o3Gk2b2N4vU [2] http://www.imdb.com/title/tt4347938/