“This is a short mockumentary from the 90s.
It features black and white archive footage of the city of New York and a voice over. It pretends, that humanity has fallen and the city of Ny (pronounced Nyyy) is the only city left.
It is, however, floating in the sky on the clouds. To emphasize this point, footage is shown of vents in the street, where you can see steam coming from.
Another thing I remember is, that it shows footage of plastic bags floating in the wind and claims it is some sort of jellyfish, attacking people. (showing bags beeing blown onto people). Supposedly, these creatures then lay eggs in the humans, which results in convulsions of their jaws (showing people chewing gum) until the eggs hatch (showing people blowing bubble gum).
It had many more of these reinterpretations. I even think the name of the documentary was called “City of Ny” but naturally I can’t find it with this title.”
https://www.reddit.com/r/whatsthemoviecalled/comments/1n8w46r/city_of_ny/