why did they kill bobby off on 911

They killed off Bobby Nash on 9-1-1 because the show's creators wanted to introduce a major death to make the series more realistic. Bobby's character contracted a lethal virus during a biolab explosion and sacrificed himself by using the only available antiviral to save another character, Chimney. He kept his infection secret to protect his team and died in a poignant, self- sacrificial moment. Showrunner Tim Minear explained that this decision was intended as a tribute to the real-life sacrifices of first responders and to bring more authenticity and emotional depth to the series. The death was also meant to open doors for new storylines, despite the shock and backlash from fans due to how late in the series it happened and the connections of other characters who could have been chosen. The decision was a difficult and deliberate creative choice rather than a cost-cutting one, and one that the network approved after much consideration.