9-1-1 has so far featured some accidents involving the emergency service team, such as Buck trapped under a fire truck, Chimney impaled, and Eddie being shot in broad daylight. But in all of these incidents, the characters survive, either saved by someone or acting just in time.
However, the show breaks this pattern and delivers the most shocking and significant death of Bobby. Why was this death significant? It reminded viewers that the team is not invincible but equally human. This also reflects real-life incidents involving emergency service personnel who risk their lives to save others.
In the season's episode 15 titled "Lab Rats," the team faces a crisis involving a deadly virus. Several 118 members, including Chimney and Bobby, are exposed to the virus. By the end, only one dose of the antidote remains. The fire department station captain sacrifices himself by giving the last antidote to Chimney, hiding the fact that he has been exposed to the virus.
Read about the whole incident here.
Here is how Bobby Nash dies in 9-1-1
A chemical lab is exposed to a deadly virus, a mutated strain of Crimean-Congo hemorrhagic fever, while the fire department is conducting a rescue. Their lives are turned upside down when many of their team members become exposed to the virus. Chimney's condition worsens rapidly, Hen is recovering from the spot surgery Bobby performed, and Ravi nearly suffocates until Bobby manages to save him as well. During this time, even Bobby gets infected.
Initially, he hides the news from others, and when they find the only antidote, Bobby makes a calculated decision to administer it to Chimney. As the team leaves the virus-infected location, Buck returns to see Nash, and their farewell is heartbreaking.
Nash closes the shutter, creating a wall and keeping himself inside. Buck realizes Nash is sacrificing himself and has quite accepted his fate. He suddenly exclaims that he cannot do that. Bobby takes off his mask as he knows he is already exposed and says one line to Buck,
“You’re gonna be okay, Buck. Remember that. They’re gonna need you. I love you, kid.”
Bobby goes inside while Buck is stunned, processing the situation and what is to come. Bobby's decision to die so his team could survive stays with Buck.
Bobby reveals to Athena how he was exposed in the first place in 9-1-1
The team members in 9-1-1 then bid their final goodbyes to Bobby through the glass door separating them. Bobby is already unmasked inside the infected lab. That is when Athena arrives and asks him, "How?" Bobby explains that there was a hole in his breathing pipe.
"There is a hole in the air supply line in my breathing apparatus. Probably happened during the explosion,"
"Why didn't you say something?" asks Athena outrageously.
"It's only one dose. Nothing I said was going to change the math."
Athena, still hopeful, instructs Buck to get the medical team; however, Bobby stops him and tells him to leave because he wants to have some alone time with his wife.
"I started feeling it hours ago. I am sorry this is not how I wanted to leave you," marks the last words of Bobby to Athena.
Showrunner Tim Minear confirms that Bobby's death was a creative decision to give the viewers a taste of reality. Bobby becomes the first major character to die in the show, therefore marking a significant turning point, changing the dynamic at the station with other characters reeling with grief and guilt all at once.