I was waiting to board a cruise ship in China and the holding area was very small. You went up the escalators to register and then back downstairs. People were entering the building where the escalators stopped. The building became so full that people on the down escalator didn't have any space to go and were falling and bunching up. I was a ways away on the upper level people watching. When I saw what was happening, I started yelling at people not to get on. They looked at me like I was a crazy lady. Finally someone got to the stop button and stopped it. It was awful. There is just nothing you can do, people keep coming and falling on top of each other. (I imagine by the time OP got to the top there was no way to find and push the stop button. They aren't usually in obvious places.)