Well, it certainly does. 23 kids dying in a shooting incident is a lot more impactful than 3000 kids dying across the nation. One impacts nearly everyone with kids in a geographical area (many will need counseling), the other only impacts a couple families in a given geographical area.
I don't even know what you're referring to here. Sandy Hook I guess? That was 27. Other than that, there have been no mass shootings in schools with that many children killed since 1927.
I was using 2018 numbers - 23 is the total number of people killed in mass shootings in or near schools throughout the US that year. It hurts to say this, but I think the sober reality is that this is a very small problem, affecting very few people. On the other hand, every community in the country is impacted by automobile impacts killing children.
I disagree thoroughly. Murder always affects those metrics much more than accident. Mass murder more than individual crimes of passion. Freak accidents more than common accidents. Et cetera.