No event on television hits quite as hard as a fictional character's death. Whether it's expected as part of a long-running storyline or completely unexpected in a major twist, a TV death can change the game for any TV show - for better or worse. Bobby Nash's death in 911 falls into the latter category in terms of being unexpected, but does it also fall into the 'worse' one? That's a question for the fans, but I'm pretty sure they would all agree that it does.
The beloved captain of the 118 met his demise in the show's unanticipated 911: Contagion two-episode event that saw its core team of first responders contend with the potential outbreak of a deadly virus. After saving chimney from that virus with the only antidote (with the help of Athena and Buck), Bobby revealed that he too had become infected. With his loved ones safe, Captain Nash died with his wife Athena nearby.
Oliver Stark opens up about Bobby's death in 911
The death of Bobby Nash on 911 has generated a ton of conversation as the departure of actor Peter Krause from the show was completely unforeseen. But it affected nobody more than the cast of the show. That's something that cast member Oliver Stark, who plays Evan "Buck" Buckley on the show, recently opened up about, revealing his genuine shock when he found out that Bobby would die.
When asked by TVLine what his genuine reaction to the news about Bobby was, Stark told him it was "silence", adding that it was showrunner Tim Minear that broke it to him on a phone call.
"I received a phone call and I had no words, and to the point where Tim Minear - our showrunner who was placing the call - said 'Are you still there?' I said 'Yeah I just don't know what to say'."
Stark also said that the showrunner called all of the cast members of the show individually to let them know the news, praising him for doing so as it was the respect that a huge moment such as this deserves. Given how important Bobby is to the show, it's understandable that all of the cast were told separately to process the information as it meant that the beloved Peter Krause would no longer be a regular part of the show.
The decision to kill Bobby off was Minear's, and that has proven to be a controversial one. Fans are still shocked that 911 has committed to it when a show as creatively wild as this one could have found many, many ways to bring him back. But more than anything, they are sad that Bobby died and that Krause will no longer be playing the 118's captain.

These are emotions that Stark describes feeling as well when he first found out about the show's plans for Bobby:
"[Minear said:] 'I've made this choice and I want to let you know ahead of time and... so, yeah, shock and obviously sadness more than anything."
Stark has worked alongside Krause since 911 first premiered back in 2018, so to say that the upcoming ninth season will mark a change for him is an understatement. Buck was particularly close to Bobby, with the 118 captain seeing the often fiery, often too laidback firefighter as a son to him. Bobby took him under his wing and taught him a lot about values, life, and the job, helping to shape him into the kind-hearted man that he is today. Buck saw him as a father figure and always came to him for advice - an action that he probably never saw himself doing earlier in the series.
Buck has tried to hold it together since Bobby died by checking in on everyone else, but he has clearly been struggling too. That will likely continue into the ninth season as the 118 get used to their new captain and all of the characters attempt to move on, keeping his presence alive in the process. Stark alluded to this too, saying that they will have "great difficulty" moving on from it.
The 911 fans, however, are campaigning for Bobby himself to be kept alive instead, holding out hope that the show will surprise them at some point in time with a totally unbelievable (and yet totally believable on this show) way of bringing him back. Angela Bassett herself (who plays Athena Grant-Nash on the show) has spoken about fans' passion for Bobby and the show, even joking that "[the casket] was closed" if the show was ever looking for a way to bring him back.
Stark's comments reflect the importance of both Bobby Nash and Peter Krause to the 911 family. Shock and sadness are two emotions that fans of the show all over the world are feeling right now and they are pretty justified in feeling that way. Nobody wanted to lose the character and it's hard to argue with the fans who feel that the show has made a mistake in killing the 118's fire captain off.