Today a little girl was spinning round and round on the railing in between the tills and I asked her nicely to stop. Her dad yelled at me, and when I said I just didn't want her to get hurt he said she was at the top of her gymnastics club and wouldn't fall. Then there was an enormous crashing sound. She'd fallen onto the next customer's item - a big box of wine glasses she'd put on the floor because they were heavy. She had to go to hospital to get glass out of her shoulders. I'm so angry.