[DUMBGRUNT]

Burj Khalifa =2,909 stairs

In my neck of the woods, stairwell lighting is on the emergency generator circuit/ battery-powered lights.

And of course, the generators and battery system are ALWAYS well maintained. Always.

https://www.10best.com/interests/explore/tall-places-around-world-number-of-steps-to-climb/#:~:text=Burj%20Khalifa%20%2D%202%2C909%20stairs,to%20reach%20the%20160th%20floor.

[Wuli]

“In my neck of the woods, stairwell lighting is on the emergency generator circuit/ battery-powered lights.”

That is not enough at a mile high. All the infrastructure, including the water system, HVAC and intenal “transport” - elevators and escalators, would need to be included in backup power demands. No one is going to get away with having mile high tenants stranded in a general blackout and suggesting they all use the stairs won’t cut it.