For faster evacuation during an emergency, elevators should be used

NEVER.

Explanation:

elevators are generally known to be faster than any staircase, if you're not running on them. but it is not at all advisable to use them while in a emergency. elevators are run on electricity, as you would have known before. if somehow, the power goes off and you're in the elevator, you'll be stuck in it. if there's a fire in building, you're locked in the lift with no escape from the flames. it is recommended rather to use the stairs. there are chances of the elevators have a high chance of getting a free fall when the cables break. but that's not that usual. since in most places, the elevators have 4 or sometimes more cables, and even 1 of them will be strong enough to hold it. and in a rare case of all of the cables breaking, in almost all places, that have an automatic break system to stop the elevator from crashing. rhe most dangerous of all is when you get stuck halfway through the elevator door, cause in most case, you get sliced. but stairs have no problems of this sort... that is why it is always preferred over elevators

need more in formation

                                                        water

a colorless, transparent, odorless, tasteless liquid that forms the seas, lakes, rivers, and rain and is the basis of the fluids of living organisms.

                                                        halon  

any of a number of unreactive gaseous compounds of carbon with bromine and other halogens, used in fire extinguishers, but now known to damage the ozone layer.

                                                  dry chemical

extinguishing agent used on class a, class b, and class c fires.

                                                  carbon dioxide

a colorless, odorless gas produced by burning carbon and organic compounds and by respiration. it is naturally present in air (about 0.03 percent) and is absorbed by plants in photosynthesis.