Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Tearjerker: The Sixth Sense
"You were never second."
"Do I make...her proud?"
The video Cole gives to Kyra's father at her wake. It's of Kyra putting on a puppet show by herself in her room. And then, because she didn't turn the camera off, it records her mom coming in with her lunch... and then pouring two cups of floor cleaner into her food, stirring it around, and telling Kyra she expects her to eat everything. Just, her father's realization of seeing one of his daughter's last moments leading directly to his wife deliberately poisoning her.
"You were keeping her sick."
In a deleted scene, Cole using his toy soldiers to recreate what are clearly real stories of the ghosts he's seen, including the families they left behind. Shyamalan even says he hated to cut the scene because of how effective Osment was in it.
In a more meta example, the way many of the ghosts died is very tragic because they're disturbingly common. Malcolm is shot by a patient he failed to help, one woman killed herself as an alternative to living with her abusive husband, another is killed in a traffic accident, a boy accidentally shot himself while playing with his dad's guns...