For individuals struggling to recover from Post-Traumatic Stress Disorder, or PTSD, for example, reliving memories of high stress and fear can trigger unwelcome flashbacks.

So wait... if you have PTSD from a previous school shooting, drilling about a school shooting is likely to trigger your PTSD? But drilling for school shootings is bad because most schools are never likely to experience one?

That said, How did I not know this was a thing?