My guess is that the vanes on the top do something to disrupt the wind and stop ...

bluehawk on May 15, 2017 | parent | context | favorite | on: Dangerous Skyscrapers Channel Wind and Sun, Topple...

My guess is that the vanes on the top do something to disrupt the wind and stop it from reaching street level at such high speeds. The vines growing between the vanes could prevent this effect from happening.