Corrected entry: Will Sawyer climbs the framework of a construction crane to get above the fire on the 96th floor. Even without a prosthetic leg, it would have taken a very long time, which isn't accounted for in the time flow of events.
Kukopia
3rd Sep 2018
Correction: The crane was on the top of the building, where Will arrived via elevator. He only climbed 10-15 floors up, not 96.