Actually I was speaking a bit tongue-in-cheek. My wife told me about the report and though the media reported on the shooting, the part about the guy pointing his gun at the shooter and the gunman then taking his own life was reported by a National Rifle Association spokesman.
But here's a site with similar stories.
https://www.buzzfeed.com/ryanhatesthis/10-potential-mass-shootings-that-were-stopped-by-someone-wit?utm_term=.wmGGWXN7Ar#.jvABNelxYX
The existence of guns in our society isn't what causes gun deaths -- it's recidivism and the inability of the justice system to deal with criminal violence. The U.S. is also still largely wilderness. You go into national parks where you can go for miles without passing another person, plus we have large, nasty predators.
With so much land and so little law enforcement, we need guns. And many of our violent offenders are already living in metropolitan areas with heavy gun control. And in the vast majority of cases, when by gun control is loosened, crime goes down and where it is tightened it tends to go up!
I'm glad we have our guns here, though in countries where there are plenty of cops and a better criminal justice system, you probably don't need them as much.