[dechov]

As an exercise of the limits of this advice, how does this apply to designing elevators, short of "never design elevators"?

[ouid]

hard brakes that apply when doors are opened manually, and an emergency panel behind which a small ladder is located.

[jack9]

The costing difference between an elevator and stairs is substantial. Especially when you have to have stairs when you get an elevator by building code.

[bubblethink]

By having a manual fail safe that operates mechanically. i.e., without power.

[OJFord]

Controlled descent to the next (lowest) floor, at which the properly aligned doors can be manually opened.