I know that fire escape stairs on the outside of buildings are still used but so are escape chutes (slides similar to those used by airlines).
Escape Chute Systems design and manufacture Mass and Rapid Emergency Evacuation
Just one Escape Chute can evacuate at the rate of 25 people per minute.
Or have 360 persons at ground level in 15 minutes, irrespective to the height.
You’re right Bebe, I’ve NEVER seen or heard about anything for those in wheel chairs and I think that was a very valuable and credible question you put out…............and the answer you got very telling.