My post was a mix of math and an anecdote about phone usage in schools because, like many HN readers (I suspect yourself included), I wouldn't otherwise have any understanding of just how detrimental and dangerous phones are to the "average" student. Here's more detail on one example to try to understand what phones are doing to kids. His high school has roughly 1,000 students. At least once a week they deal with some catastrophic, potentially life changing issue related to phone usage. My school principal friend says "blah blah blah":

He walked in his office one day and a police officer, school staff, and a district attorney were in the conference room with multiple phones on the table with strategically placed Post-It notes on the screens. Again, he deals with this on a weekly basis so he knew immediately what was going on...

Turns out a student wanted to take revenge on another student who "stole her boyfriend" or something. She obtained a nude photo of the target student and posted it across all of her social media accounts - including Facebook where she was "friends" (for some reason) with at least two known adult sex offenders.

The district attorney and police had to explain to her that she could be looking at thousands of counts of disseminating child pornography. Obviously this is a scare tactic but imagine the trauma to all students involved. Meanwhile, he routinely says "these kids swap nude photos like baseball cards" so at the exact moment he's dealing with the student, police, etc this child pornography is flying through the phones of the student body - in school. Imagine the bullying as a result...

Then there's the time a student e-mailed a pornographic video (with children) of another rival to his official school e-mail account, again to settle some kind of score. It goes on, and on, and on. This is one average school in a small midwestern town with 1,000 students. There's no way reason to think these experiences are in any way out of the norm. However, due to the sensitivity these situations obviously aren't communicated in mass media and needless to say your kids aren't telling you about the naked pictures of a classmate they've been sending around all day.

Ask one of the parents who deal with this situation (every week, at one school) how concerned they are about school shootings in that moment.

Additionally, if a parent has a problem with a 1:2500 chance of a student even being exposed to a school shooting, ask questions like:

- How many miles do you drive? Do your kids have a driver's license? Do their friends? How many miles do they drive? What are the safety features of every car they've ever been in?

- Do you have a swimming pool? Do any of your kids friends have a swimming pool?

- Do you personally have guns? How many of your kids friends parents have guns? What do your kids know about guns? Have you talked to all of your kids friends parents about potential ready access to guns?

- What's your healthcare situation? Do you have ready access to mental health resources? How involved are you in the lives of your children? Are you capable of recognizing the (often very subtle) warning signs of depression, self-harm, eating disorders, etc? Same for drug use.

- What social media apps are your kids using? How many accounts do they have? Do they know who all of these people are? Are they friends with any adults (and from my anecdote - any child sexual predators)?

All of these things and many more are a significantly more likely threat to the health, safety, and wellbeing of any child and I would hope that when educated, and when able to look at things rationally, parents would move the issue of school shootings further down their list of concerns for their child where it belongs. I, personally, remember several classmates dying from these causes in high school twenty years ago. Given the numbers, you likely do too.

Children (and people generally) cannot be kept in a hermetically sealed bubble. The fact is we all take actions daily that have significantly higher risks of death and injury. Driving at 70 MPH puts you a split-second away from death or debilitating injury at any moment, yet parents think nothing of traveling thousands of miles on roads with their children every year. Not directly supervising a child near any water can kill them within a few minutes. Your child can go from happy and healthy to dead from suicide or drug overdose in a moment.

If you want to do math on all of these and more you will find that you have a very poor position regarding the actual risks of school shootings, not to mention the base premise (as other commenters have noted) that phones are actually a negative in school shooting scenarios and likely actually contribute to them occurring in the first place.