Writing an Emotional Scene

A while back ago when I was working on an emotional scene in my book, I was wondering what exactly it is that makes a reader cry.  Why can we cry during Dear John or A Walk to Remember?
It's not a matter of wording.  You can write as much as you want, you can add in the most tragic details (depending on what is happening), but the words aren't really what make us cry or have an emotional attachment to the scene.  It's the depth, it's what we'll remember while that scene is happening.
You can describe a train crash and a young teenage boy who died, but no matter how much detail you go into, your reader can never truly feel connected to that scene.  They didn't know the boy, they weren't on the train, and while it's sad... there's nothing else to it but being plain sad.
However, if you had talked about this little girl who knew the teenage boy and how she adored him, looked up to him as a role model, followed him everywhere he went... that would have an affect.  Do you know why?  Because you feel attached, you would have a reason to care.  Showing how totally horrified and torn about the little girl is over that boy's death would be more powerful than any amount of words you can write on paper.
Just the other day I was watching The Vampire Diaries --yeah, I know what you're thinking, but to me those kind of shows give me inspiration to work with; after all, they were originally books [and good ones at that!]--and in one of the first episodes of season 3 (I'm catching up), Stefan calls Elena.  She answers the phone and says something along the lines of, "Stefan?  If this is you, it's going to be okay.  I love you, Stefan. Hold onto that.  Never let go of that." Then they returned the camera focus to Stefan, and though he didn't say anything, it was his silence that was the most powerful part of that scene.  He started crying, and he isn't usually one to cry unless something's really wrong, and at that point I started crying too.

Later on, I thought back to that scene, and I realized it was because the writers let us know who Stefan was that the scene was so powerful.  I wasn't crying because I thought Elena's words were powerful, or because it was sad that Stefan was crying, but more so that he had been so gravely affected by her words, and that even in his darkest moment he was able to reach out to her and she seemed to be able to save him.
It's moments like those that you'll want to create, the moments that your readers will never forget and always want to return to.
Don't be afraid to reveal your character's fears.  And chances are if you start getting teary-eyed during a scene, your readers will too.
Lindsey R. Sablowski