These events are now so repugnantly routine that Americans are likely becoming inured to this USA-specific brand of sporadic mass violence, most often with killings in the double digits.
There will be no safety or control measures taken as long as this country suffers under right-wing minority rule. The Electoral College, gerrymandering, voter suppression, Russian interference, and over-represented-low-population Red States have the entire U.S. chained to the hard-right-wings insane, self-destructive addictions: irrational resistance to government as an engine of progress; white supremacy; complete denial of science and distrust in public/higher education; privatization of everything in sight, even if it means monetary losses and feeds corruption; infantile, vengeful religious beliefs; a cult-like, unswerving devotion to their ideological figurehead, and fetus/firearms worship.
Those who wave the flag hardest are those who know the least about their own country, and how it best relates to the world around us.