Even if they were on the ground floor I would stay in. Outside they might get hit by stuff falling off the building even under conditions where the building itself survives. If the building collapse, they won't be safe at all even outside the building unless they get pretty far away.

Each skyscraper should have one or more playground-style spiral slides installed that can be ridden directly to the bottom in the event of an emergency. This would also provide a valuable source of fun to the building occupants.

That would be pretty dumb in reality, but I wonder if it could be made to work... you'd need some kind of synchronisation control on the ingress to ensure people enter the slide with sufficient clearance before/ahead of them, and you'd have to have a "mantrap" type arrangement at the ingress points to prevent multiple people cramming in at once and risking a jam. You'd also want to neck the entrances down to about 3/4 of the tunnel diameter to stop overly large persons from entering the slide.

Probably also want some kind of low-friction mat at the exit point so people aren't piling up at the bottom of the slide and blocking it if they can't move fast enough.