I am curious of how it dropped 84 floors and nobody got seriously hurt.

Sounds like a bullshit story to me

Reading the CBS story tells the jist of it. One broken hoist rope, the occupants stated the cab “careened” down the hoist way, but all were rescued without any major injuries. I’d imagine if 90-something floors of rope came crashing down on a cab I was in while moving, I’d pee my pants too. Blind hoist way rescues are tough, which evidently this was.
What’s amazing to me is that firefighters could locate the cab, cut or hammer their way through a concrete wall and extract trapped passengers. Luck or what?

The investigation shows elevator did not drop or fall. Hoist cable snapped and hit safety plank switch that caused elevator to stop at 12th floor.
Otis elevator mechanics did a great job locating elevator in hoistway and recusing people.
Chicago Fire Department knocked out cinder block wall to get Otis mechanics to front of cab.
Otis Elevator Company should be proud of those guys, CFD was not prepared for this kind of rescue that led to confusion in the Chicago Fire Department and it showed in building.

Ha! Exactly what I predicted...

The media here in Australia is a joke, never a mention of elevator techs aiding in the help of rescuing passengers, always only the firemen.

Interesting to find out why the hoist cable snapped?

If one suspension rope broke, I would imagine it was carrying most of the load,and it needed to be re-tensioned. Unless a shackle let go somehow. It is all conjecture, supposition and bullcrap, until they inspect it. I feel sure a field guy will get the blame somehow.

Pieces of rope could have fallen towards pit and jammed comp switches, gov tie-downs, buffer sws, etc. Something stopped the car in the blind hatch. We know it did not fall 70+ floors.

Building owner/ management companies are taking lowest bidder now for elevator maintenance. Companies are dropping prices to keep buildings. When that happens the elevator mechanics don't have enough time for correct maintenance .
Did Otis mechanic get on cartop and run hoistway to inspect cables every month on all elevators? Probably not, time and money are key factors.
Not enough maintenance hours?
Otis pushing back cable job?