I have no landing pads or teleporter, just a few elevators. In general, most of the city is less than 10 stories high. I have created a pastebin of the save, in case anybody wants to look:
https://pastebin.com/CLFaiSjG
Last update: My city managed to produce exactly nothing the last day. With an amount of buildings, that could produce over 1000 food and 300 stone. Just nobody left his home. Ok, people are very unhappy by now, but even a reduction to 25% should not yield nothing. Moreover, food should not be reduced. Seems like a horrible bug to me.
Just to illustrate the problem: My food production of some consecutive days: 841,807, 360, 321, 233, 399, 593. I have also seen my food factories producing way over 1000. But for some reason the people decide not to work properly. The stone production of the same days: 277,294,81,92,60, 24. Last day is off, because people were starving by then. But the rest look like a flat reduction of productivy for all goods. Reason unclear. I think about abandoning the city and the whole game.
Something is really wrong here. Sometimes production (for everything) will drop to small fraction, without any reason. People just stand on the streets and do nothing. Few days later they suddenly decide not to starve and all production is back to normal. Absolutely erratic without any visible reason. I have no idea how to deal with this.