Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Tear Jerker: The Pendragon Adventure
Black Water: Kasha's death. This strong, brave warrior is reduced to a lost kitten as she approaches the brink of death. Bobby is about to leave to try and get help, but she begs him not to go. He looks at her, and realizes that what she needs at that moment is someone to stay with her. So that's what he does, sitting with her and holding her paw until she's gone.
The Pilgrims of Rayne:
Courtney's confrontation with Mark on the ship, when she remembers how Mark supposedly died, realizes that she was the one to kill him, and pulls a gun on him. Thankfully, it doesn't go the tragic route, but Courtney being driven to such desperation is just awful regardless, especially seeing how the two have slowly become good friends throughout the course of the whole series.
Bobby's last journal of the book, which he wrote believing that he would never return home again.
I don't know if this is the way it was meant to be, but it's the way it's going to be.