Editor's Note: The following contains spoilers for 9-1-1 Season 8, Episode 17.Killing off a show's main character is a tricky endeavor to pull off. In the rare cases that it's been done well, like with Game of Thrones' Ned Stark (Sean Bean), it can change everything for the better. What doesn't work is when this happens eight seasons into a show with a carefully crafted tone where it's been established that the main characters will never die. As such, 9-1-1's truly mind-boggling decision to kill off Bobby Nash (Peter Krause) has completely upended and fundamentally changed this series. This unprecedented tragedy has turned 9-1-1 into what feels like a new show, where every once-familiar detail is now just off.