The article contains major SPOILERS for 9-1-1 Lone Star season 4, episode 6Tim Minear, showrunner of 9-1-1 Lone Star discusses Agent Casey's (Amanda Schull) shocking death. Although the law enforcement procedural, and the wider 9-1-1 franchise, is no stranger to surprising departures, the latest installment ups the stakes. 9-1-1 Lone Star season 4, episode 6, appropriately titled "This Is Not A Drill", sees an explosion that kills nine FBI agents. That includes Agent Casey, who spent some of her last moments being annoyed by Owen Strand (Rob Lowe) over a disagreement.
https://screenrant.com/911-lone-star-casey-death-showrunner-response/