What primary risk do elevators pose during a fire evacuation?

Elevators pose a significant risk during a fire evacuation primarily because they may malfunction. In the event of a fire, elevators can become inoperable or may descend inadvertently to floors affected by the fire. This can trap individuals or lead them directly into harm's way, as elevators are typically programmed to return to the ground floor automatically during emergency situations, which could expose occupants to smoke or flames. Additionally, power failures caused by a fire can prevent elevators from functioning entirely, leaving individuals stranded. Therefore, the inherent uncertainties and potential malfunctions associated with elevator operation during a fire emergency make them a critical safety concern.