This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / The Day After
Eve Dahlberg, in deep-seated denial, stubbornly tries to continue doing housework despite the fact that there is only a few short minutes to nuclear armageddon. After a brief struggle, Jim starts to drag her down to the cellar, while she bawls loudly in despair the entire time ...
Denise Dahlberg toward the end of the movie. "They gave me this ribbon to wear ... but I haven't got any damn hair to put it in to ..."
A deleted scene reveals the purpose of the ribbon. It's color-coded, meaning certain to die, do not waste medical attention.
Made even worse if you know that this is an actual practice in Real Life. Actual plans in case of actual nuclear disaster involve clipping morgue toe tags to still living individuals and other fatalistic symbols. It's a triage situation - they can't afford to waste precious resources (including the time, care, or attention of medical staff) on people who will die anyway just to spare feelings.
Made even worse by the fact that her entire family is most probably dead (except for her brother, who has been blinded by the nuke blast)-father nonchalantly killed by a squatter with a shotgun when he tried to protest them being on his yard, and it is implied that the squatters killed her mother and youngest brother afterwards.
Just as the war starts, Denise, who had been trying to assert her independence, is clutching a stuffed animal as she heads into the basement, reduced to a frightened child.
During evacuations of the city, a girl asks her dad if they have to go down, and an officer tells them that they have to go down. Later, during the nuke attack, people are rushing to the shelter, and a shot reveals they are trampling down the girl.
After the radiation goes down enough to go outside, the Dahlbergs and other local survivors go to the ruined church, where the pastor attempts to hold a service. Denise passes out bleeding in the middle of it, and is carried out by her family. The pastor attempts to continue the sermon, but breaks down crying as the scene ends.