I had planned on talking about the school situations currently going on, and I still will, however I've decided to go with guns first.
A well regulated militia being necessary to the security of a free State, the right of the People to keep and bear arms shall not be infringed.
This amendment does not apply to hunting. It's main purpose is to allow the people of the united States to defend themselves from the possibility of their government becoming corrupt. Simply put, its so that our federal government will fear its own people's response to any laws or regulations it might try to pass. To put it another way, people who fear their government are subjects, a government which fears its people has citizens.
"When the people fear the government you have tyranny. . . when the government fears the people you have liberty."
However, it goes deeper than that as well. It's not just self defense from the government that's our right, but also self defense from criminals. The people of the united States have the right to bear their firearms at all times. Its said that one armed man can control one hundred unarmed people. Take a bank robbery for example; You've got one to four armed robbers, and perhaps up to fifty (depending on the size of the bank) unarmed hostages.
Now imagine a bank, we'll say there are twelve customers, and fifteen employees throughout the building, all of which are armed and know how to use a gun. Four guys enter and draw their guns. In response, all twelve customers and four tellers draw their guns, one or more of whom alerts the rest of the staff of an attempted robbery, the remaining eleven employees appear, all bearing firearms. Suddenly the attempted robbery isn't a problem any longer, and the police have been notified and are on their way.
Guns in the hand of law abiding citizens are not dangerous to anyone who isn't threatening them. Guns in the hands of criminals are. Criminals have already shown that they have no trouble getting a gun, even when they can't buy one legitimately. So, if you're willing to break the law, you can get a gun much faster than someone who wants to get one honestly.
Rather than forbidding guns on school property, require that all teachers and staff carry a firearm. Instances like Columbine happening would drop drastically. The same goes for businesses.