A man is at a train platform. He wants to get on a train, but he slips. He falls down. His leg is between the train and the platform. This is a dangerous situation.
People want to help him. People on the train move to one side of it. They want to move the weight of the train away from him. Sadly, this plan does not work.
Everybody gets out of the train. People push it. They give the man more space and save him.
He is OK.
Difficult words: platform (area from which you get on the train), slip (moment when you cannot control your body and you fall), weight (how heavy something is).
You can read the original story and watch the video in the Level 3 section.