I'm really sorry - that must've been terribly upsetting, but you had the best of intentions and everyone gets nervous about what might be precisely the right thing to do. As soon as you saw it you were clearly thinking only of what you could do to help. I do hope you can be less hard on yourself in time: after all, there were lots of stages leading up to this, and probably someone's kicking themselves over not mending a gap in the fence or something as well.