If you look up professions with the highest death rates. Teacher's are fairly low on the list, if they show up at all. https://www.insidermonkey.com/blog/15-professions-with-the-h...
The statistics of it being improbable to die at school are no salve.
"The Education Department reports that roughly 50 million children attend public schools for roughly 180 days per year. ... That means the statistical likelihood of any given public school student being killed by a gun, in school, on any given day since 1999 was roughly 1 in 614,000,000."
So in a given (180 day) year, such a child has a 1 in 3.4 million chance of dying, which means the equivalent annual death rate out of 100,000 children is 0.029 children.
The article you link to says that the annual death rate per 100,000 "Police and sheriff’s patrol officers" is 14.6 which is a few orders of magnitudes bigger, although children don't have as much control over whether they go to public schools as cops have over which job they do.
[0] https://www.washingtonpost.com/outlook/school-shootings-are-...