help me think of the name of this movie

I saw a clip from this movie a while back, and I don't remember anything else about it.  In the clip a man remembers his past where he throws a rock at a boy in a tree.  He hits the boy with the rock and the boy falls from the tree to his death.  The movie was probably made in the 90s and seemed to have a dark tone.  What's the name of this movie?

The movie you're looking for is Flatliners.

Its about medical students who try out the idea of flatlining and reviving each other in hopes of having unique experiences. They end up unleashing shit they've repressed and have to come to terms with.