What was the saddest thing you've ever seen/experienced in a video game?

for me, it was killing Toriel in Undertale, basically i wanted to spare her but didn't know what do to, so after trying all the options and failed (wasn't aware you were supposed to keep pressing spare until she eventually stopped fighting), i hoped that if you'd bring her health down to zero you'd then be given the option to spare her, and much to my shock and horror, all that happened when her HP went to 0 was her sprite dissolving into dust and her soul breaking, to say i was sad would be an understatement, Toriel was one of the kindest characters in whole game and one i'd have the least wanted to kill, even worse here being that i had the possibility to spare her but failed, it upset me enough that i didn't booted up the game again for several days