The law of large numbers means that horrific, improbable events will happen from time to time in a country of >310MM people.
There are actually two mortality risks Americans face that I find shockingly low. One is the risk of dying in a commercial plane crash. It is absolutely remarkable that a plane carrying thousands of gallons of jet fuel, with engines the size of automobiles, can travel at 150mph on the ground, rise tens of thousands of feet into the air at speeds reaching 600mph, travel thousands of miles, and then land on a narrow strip of asphalt less than two miles long, all while being controlled by a human being, and still have less than a 1 in 10MM chance of crashing.
The other risk I find to be surprisingly low is the risk of dying in a random mass shooting. There are over 200MM privately owned firerms in the US, and over 50MM households have at least one firearm. And yet random mass shootings occur at the rate of fewer than 5 per year, and those involving children are much, much less frequent. If we define an opportunity for a mass shooting as one year of access to a firearm in the home, then the probability of one such opportunity turning into a mass shooting is comparable to the probability of a plane crash. That is, if you lived next to a gun owner, and you somehow managed to convince him that if he were to go on a random murderous rampage with his gun during the next year, that he should shoot you dead first, just as a courtesy, then your increased risk of dying over the next year would be equivalent to the risk of taking a one-way trip on a commercial plane.
I think it almost goes without saying that the risk of dying in a random mass shooting (or any shooting actually, as long as you’re not a criminal or suicidal) is so small as to be negligible compared to other risks in life, and we should waste no more time or resources on the problem unless evidence arises that the risk is increasing by orders of magnitude. In fact, the statistics show that the risk is actually decreasing. Despite the increase in US population, the frequency of mass shootings has stayed relatively constant, and the rate of shootings at schools has actually declined.
The real lesson of the Newtown massacre is that we should not let statistically insignificant events be blown out of proportion by the media and by our own emotions. The coming push to enact new laws to restrict our liberties, whether they involve the right to own and carry a gun, the right to have a weird personality, or the right to produce and consume media with violent content, should be opposed vigorously. If media focus on exceedingly rare (but statistically inevitable) tragedies allows the ratchet of liberty-reducing law-making to progress with each event, then we will become less free over time. At times like this, it is worth recalling Benjamin Franklin’s famous maxim, usually paraphrased for dramatic effect as: “Any society that would give up a little liberty to gain a little security will deserve neither and lose both.”