I would stay simply because when a person is in trouble I often feel that I should help them, even if I am unaware how to help them. I'd probably leave after a bit when I figured out there is nothing I could do.
Still, it always tugs at the heart strings a little to know that we are such strangers to one another that when we hear another soul cry out in pain, the usual response is to be a voyeur or ignore it. Maybe if we all wanted to help this sort of thing wouldn't happen, but I can't say for certain. Maybe I can stand directly under them so they see that someone is willing to catch them or die trying. Who knows?
That was a great response. I can't think of anything better to say after that.