Typical. Something bad happens and the response is more control, more government, more loss of liberty.
The worst school massacre in the US not during war involved explosives and no firearms. The explosives were planted over the course of months. The attack killed 44 and wounded 58. It was carried out by Andrew Kehoe in 1927, the attack took place at Bath Township in Michigan. It was also probably the first suicide car bombing perpetrated in the United States.
The Columbine School shootings were planned over the course of months and did not just involve firearms, improvised explosives were also involved and it was due to failure of design that those explosives didn't kill more people than the guns.
Attacks on schools and murder rampages in general are not isolated to the United States. In China you have had attacks on schools, usually involving knives because China is an authoritarian police state where the state has a monopoly on firearms. You had the Cumbria shootings in the UK, the weapons involved were a double-barrel shotgun and a bolt-action .22 caliber rifle, no assault weapon or high-capacity pistol, 12 dead and 11 wounded, the UK had already banned handguns due to an earlier rampage. The perp in this case was not stopped by police, he was last seen alive at 12:30 local time and his body was discovered a couple of hours later. In Norway you had Anders Breivik kill close to 100, and Norway has very stringent gun control laws. Walter Siefert used a home-made flamethrower, a lance and a mace to kill 11 and wound 22 at the Cologne School Massacre in 1964, no firearms were involved, the perp suicided by ingesting insecticide but didn't die till the next day.
In a lot of these cases, law-enforcement does not stop these acts in the process but get their in time to identify the body of the shooter who takes his own life.
You cannot prevent such acts by deranged and highly motivated individuals without an authoritarian state like China, North Korea or as seen in Eastern Europe during the Cold War. If you really want that I suggest you move to North Korea.
This elementary school was a Gun-Free Zone. So was Columbine. And Virginia Tech. These gun rampages do not happen were a lot of gun-armed sheepdogs are expected to be present such as at a gun-show, or range events such as Machinegun Shoot at Knob Creek. If anything you should expect it at Knob Creek's Machinegun shoot where people bring weapons with rates of fire upto 100 rounds per second. It does not happen there. Why?
Simply put, gun free zones are a false sense of security. A Gun Free Zone is a gigantic sign for psychopaths that say 'You can kill here, no one can stop you!' It disarms precisely the people you want to be armed, the overwhelming number of people who are decent, responsible, law-abiding and care for the people around them.
Gun control is also a false sense of security as well. A criminal can get a gun within 24 hours. We cannot stop drugs and people from illegally entering the country, think we can stop a load of guns. And again, it disarms precisely the people you want to be armed in bad situations. It is like a gun-free zone, it does precisely the opposite of its stated purpose.
Violent and gun crime rates continue to drop as gun ownership rates increase. More guns equal increased safety. Want to stop further school rampages? Here is how. Take the stay at home mothers of the students, organize them into a militia, arm them with AR-15s and have them guard their own children. Problem solved.