Isn't this every mother's nightmare? (Potential spoilers!)

I have seen this film multiple times, and every time I get to the scene where she finally finds her son and realises she unintentionally killed him, just because she wasn't quick enough to realise the game he wanted to play with her, it just gets to me on a totally other level than other films.

I don't want to go in to the Whole "was it real or not"- thing, because the point is, it doesn't really matter. What matters is, a mother loses her child, and goes totally, tragically crazy and kills herself when she realises she killed him without knowing it until she found him.

Which brings me to the title of the thread. I don't have children yet, but my youngest Brother is 6, and I know I would be heartbroken beyond belief if I accidentally harmed him in any way. So those of you who have children, does it get to you that this could, in fact, happen to any parent? The "accidentally doing harm to your child"-part I mean.