Even at the Parkland school shooting. The 11th Circuit notes,

“The students allege that the Parkland tragedy was exacerbated by government blunders before and during the shooting. The Broward County Sheriff’s Office failed to act on the “many dozens of calls” it received that warned of Cruz’s dangerous propensities. Although Sheriff Scott Israel and Superintendent Robert Runcie knew that Cruz might be dangerous and Runcie was warned that the school had inadequate security, neither official attempted to improve school security. And Scot Peterson, the police officer in charge of school security, was nicknamed “Rod”–short for “retired on duty”– for his “lackadaisical . . . approach[].”

On the day of the shooting, Andrew Medina, a school security guard, recognized Cruz as a potential school shooter but permitted him to enter the school anyway. Medina radioed and texted other security officials that Cruz–a suspicious person–was present, and he drove a golf cart toward Cruz. But he did not directly approach Cruz or call in a code to put the school on lockdown. Medina later explained that he was ordered not to call in a code unless he saw a gun, so he did not call one in even after he heard gunshots.”