Falling Down

In the underground after the Netural route, Asgore dies, Omega Flowey kills the human, gets slayed by Undyne, becomes the new queen/Hitler of the underground,

And three little children have been caught into this by

Falling Down
Leaving Toriel
Scouting the Snow
Avoiding the Sleeper
Solving the Puzzles
Wading through Waterfalls
Through The Cave
Sparing Monster Kid
Saving The Corrupted
Fearing the Science
Praying for a miracle
Death by chainsaws
Finding the Wilted Flowers
Killed by Undyne
Resetting once again