Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Tear Jerker: Catch-22
The latter parts of Catch-22. A story that had been lighthearted and bizarre suddenly takes a turn for dark territory, killing off a lot of the characters, and the second-to-last chapter that details Snowden's death.
Yossarian's memories of the dying Snowden. "I'm cold."
After Orr is shot down over the ocean, Yossarian reassures himself that Orr will manage to survive and make it back, like so many times before. He then waits in his tent for Orr to return, for a long time, telling himself that Orr is going to come back aaany minute now...
The chaplain breaking down in tears, when he learns Nately has been killed.
The part where the completely bandaged Yossarian has to pretend to be a dying soldier named Giuseppe in front of Giuseppe's parents (the real Giuseppe having died recently, and the hospital staff not wanting to disappoint them). Sure, it's pretty funny, but it's also kinda sad.
Also, the deaths of McWatt and Kid Sampson, McWatt especially. Arrgh. McWatt accidentally slices Kid Sampson in two while flying low in his plane for fun, and when he realizes what he had done he has the entire crew jump out on parachutes, then flies into a mountain.