Liftbuild nears completion on remarkable "top-down" skyscraper
An awkward, triangular site near the Greektown neighborhood was chosen for the project, since according to the developers, it wouldn't have been possible to build a tower of this height using traditional construction methods - the elevated People Mover system running right next to it would've prevented the use of tower cranes.
https://newatlas.com/architecture/liftbuild-top-down-construction-exchange