Have just read an article about a 4yo in Fife who was left behind at a wildlife park when on a nursery trip (DM article so I won’t link it!).
All kids had been told to go to the toilet before going back on the bus, he’d been last in the queue and when he came out they had left.
I believe another park visitor alerted park staff that there was a child alone and they then contacted the nursery staff who made the journey back to collect him. They hadn’t even noticed he was gone!
3 staff to 9 kids. How on Earth does something like that happen?! Poor child must have been so worried!