Well, I think in this case it was actually a jump rope that was somehow tied to the structure, so not exactly what you're talking about, but still, this story has made me very wary of ropes on play structures:
http://abclocal.go.com/wabc/story?se...al&id=5397745#
http://abclocal.go.com/wabc/story?se...al&id=5397745#