Child disappearing under train caught on camera

Child disappearing under train caught on camera @ Yahoo! Video
So how did the girl survive?
She and her mother are trying to get accross the tracks to avoid paying the ticket. When the train is coming, the girl was already on the tracks while her mother was getting down the tracks, immediatly her mother climb back to the platform on time while the girl went under the platform. Then, the train arrived at the station and luckly, the girl was not injured at all.