When a ski lift becomes permanently stuck and cannot be restarted via its backup motor, ski patrol initiates a "vertical evacuation." This is a highly coordinated rescue operation that must typically be completed within a 3-hour window for safety. Specialized "aerialists" from the rescue team climb the lift towers and use a "cable bicycle" or rollers to slide along the haul rope to reach individual chairs. Once at the chair, the rescuer secures themselves and then lowers an evacuation triangle (a specialized harness) to the passengers. One by one, passengers are secured into the harness and lowered slowly to the ground using a belay system managed by team members on the snow below. In some extreme cases involving gondolas or very high spans, helicopters may be used to winch passengers out, though this is rare and weather-dependent. Throughout the process, the most critical part for passengers is to remain calm and stay seated; attempting to jump or climb out of a chair is extremely dangerous and is the leading cause of injury during lift malfunctions.