Making guns illegal only takes them out of the hands of law abiding citizens who use them for protection or recreation (hunting, sport shooting). If you took more of an interest and did some in depth research you'll find that Gun control laws here in the US do NOT reduce gun related crimes. Why take away guns from people who use them properly and legally? You think the majority of criminals purchase their firearms legally? The answer to that rhetorical question is a resounding NO. Take for instance Florida. They not only allow law abiding citizens to own guns, you can apply and obtain a license to carry a concealed weapon. Now although gun violence did not drop significantly, it did not increase. And when you did into the statistics the gun related crimes against Florida citizens dropped dramatically. When incarcerated criminals were questioned as to why this drastic drop of violent crimes against Florida natives/citizens the majority answered the same. "You never know if a resident owns or is carrying a concealed firearm."
The question I pose you, is would this have happened to this degree if someone in that room was carrying a concealed firearm for protection?
It's a shame shootings like this happen. No, I digress its more than a shame, its an abomination. But the answer isn't taking guns from people who legally obtain them and use them for legal purposes. Figure out why these deluded individuals believe that its alright to shoot and kill innocent people. Take it seriously when you hear a classmate or acquaintance talk about committing a crime like this. Don't just chalk it up to "Oh, s/he must be joking". Many (not all) of these tragedies could have been averted if people gave two ****s and used common sense.
And sometimes there just isn't a reason. What happened to just plain "crazy" people? Why do we always have to find some deeper, underlying symptom or problem? What happened to some people are just "broken", or not "right" in the head.
I can't imagine how the families of those six victims feel, and I also feel for the family of the shooter. Not the shooter himself, but the family of the shooter. Because they have to live the rest of their lives with knowing that their loved one needlessly ended the lives of innocent people. And they will probably ask the same question "Could we have prevented this?".