There’s nothing graphic in the clip, I promise. Not a single shot is fired. Rather, the fear comes from having to put yourself in these kids’ shoes as they shelter in place during a mass shooting.

If the room you’re in is locked and someone comes banging on the door declaring that they’re a cop, do you open it?

What evidence would you need to assure you that the person on the other side of that door is a police officer and not the shooter telling a lie to gain entry?

For these poor kids, it all came down to the word “bro.” Here was the scene at Oxford High School in Michigan, where four students were murdered yesterday by a 15-year-old on a rampage:

A student from inside Oxford High School captured this footage of the possible shooter trying to get into the classroom by impersonating a sheriff

The students did not open the door and escaped through a windowhttps://t.co/DCKb6l555w pic.twitter.com/gQWOuJPAAL

— philip lewis (@Phil_Lewis_) November 30, 2021

The fact that there was an officer waiting for them across the courtyard to assure them that they’re “fine” strongly suggests that the guy banging on the classroom door really was a cop, proceeding through the now-secure building to let the kids out. His voice is deep and sounds like an adult’s too, not a 15-year-old’s. And according to news reports, the shooter was in custody within literally five minutes. There wouldn’t have been much time for him to pull the deception suggested by the clip.

But no one faults any student there for assuming the worst. “Oakland County Sheriff Michael Bouchard said on Tuesday night that officials had been told that the gunman pretended to be law enforcement to try to gain access to barricaded classrooms,” Insider reported, although it’s unclear whether there’s evidence of that beyond the (apparent) misunderstanding in the clip above.

More than one student said afterward that the training they’d received on what to do during a mass shooting helped. “Like many Michigan students, [Barrett] Dolata said he has been trained in active shooter drills in school and knew to barricade the doors and gather in a corner,” per the Detroit News. Another told Fox Detroit, “Yes it did (help), everyone was serious (and knew what to do).” Even the sheriff’s office credited lockdown training in a statement afterward:

“I just left Oxford high school after a detailed walk-through and examination of the scene and evidence. As I reflect on the day, it is one that is filled with overwhelming sadness. My heart aches for families that will never be the same and a quiet sweet community that had its innocence shattered. I have seen far too many bodies and death in my career, but children’s are always the worst. I am super proud of our team as they continue to work through the night and I know the work they did this day saved lives. It is also evident from the scene that the lockdown protocols, training, and equipment Oxford schools had in place saved lives as well. I will close this day with more prayers, as we will be back at it in a couple of hours. “

The fact that kids are being trained in what to do when a classmate opens fire on them feels like a fall-of-civilization omen, but I suppose the real omen is that it actually is necessary and useful.

The four students killed were Madisyn Baldwin, Tate Myre, Justin Shilling, and Hana St. Juliana, the last of whom was just 14 years old. There are reports that Myre was shot while trying to disarm the gunman. His classmates are pushing to have the school’s football field renamed after him to honor his memory. He was 16.