Actually happened to us once! We were helping our daughter to get the train home with her baby in a pram and her bags, very crowded platform, OH lifted the pram onto the train, I took one of her bags and the train suddenly moved off, daughter on the platform with her other bag! We had to get off at the next station, 40 minutes away, wait for the next train back. Luckily the baby had just been fed before we got to the station.