In 5th grade my teacher organized a field trip for our class. It was about 15-20 children and 3-4 adults, including her. The parents volunteers drove their own cars and we all squeezed in. When we got there there was two (or three) carloads that arrived but we were still waiting on the last group of people. We were allowed to explore the outside-the-park gift shops while we waited and kept checking back in with our teacher. About 30-45 minutes passed and they still hadn't arrived.
Next time I try to check with teacher I realized everyone is gone. Completely. I spend HOURS wandering from the gift shops to the front gate, to the parking lot (to check and see if the cars are still there) and back to the front again. I had the park call for my teacher over and over on the intercom and she never replied. They told her later that the inside-the-park intercom system is separate from the outside-the-park intercom system so they never heard the calls.
I'm not sure why I didn't call my parents. We were not close to home. Knott's Berry Farm is about 1 1/2 hours away but I was locked out side for about 10 hours. None of the park employees did anything to help not called a manager, police, my parents. I just kept wandering around and making sure the cars were still there. I don't even think I had any food this whole time.
This was about 30 years ago, so pre-pagers and cell phones. I could have called home on a payphone but never did.
About 10pm my teacher and all of the other children came walking out of the entrance. I was trying not to cry and started choking on my gum. My teacher yelled at me for crying, saying it was uncalled for, and said she'd assumed I was with another parent, in the split-up groups, the whole time and she never knew I was missing. Now, as an adult, I can't imagine what was going on in her head. Maybe she yelled at me for crying to cover up her mess-up and all that could have gone wrong. Not one adult knew I was missing the entire time.
We all got into the cars and went home. It was never mentioned at school. I'm not sure my parents ever knew. She never gave me a refund for my ticket.