Ah, I was there around then, on my lunchbreak with colleagues. Jaya came down and stole it from her. I do wish kids would refrain from chucking things in the enclosures, as it means that barriers move further back all the time.
I had thought that the school groups were well behaved till then, and they seemed to have supervisors with them, not something that happens in every zoo.
The worst thing that we've had happen is a visiting French schoolchild dropping a nintendo gameboy into the red river hogs - which Noah proceeded to munch to pieces. It could have been disastrous . Since then, we have 'improved' fencing, but it means viewing is far less 'up close' than it was.
Local children are generally pretty well behaved, and oddly habituated, as all Jersey schools get at least one visit per class, per year, plus activities with our Education Department. They 'grow up here', so to speak, and generally have the rules in place from nursery age... it's lovely to see!