Nuclear Duck and Cover by Tyler Wigg-Stevenson

It’s hard to write these sentences. I’ve started this article a dozen times, only to erase in frustration. The simple fact is that there’s no easy way to bring up the need to be prepared for the unthinkable. It’s one thing to bring up the threat of nuclear terrorism as a problem to prevent, but it seems almost embarrassing to talk about it as something that could happen tomorrow, though of course it could. Americans have a lot on our plates right now, from rising concern about income inequality, to joblessness, to a world that seems ever more unstable and uncertain. Introducing something like nuclear weapons into the mix feels like unreal overkill, like freaking out about killer asteroids instead of the home foreclosure papers sitting on the kitchen table.

But there doesn’t appear to be any way around the fact that uncertainty is the condition of our age. In recent years, people have begun talking about “black swan” events—things that seemed so impossible, we didn’t even include them in our contingency planning, and we’ve got no way to deal with them when they go down.

Over the past decade, we’ve had ample evidence of the impact that these kinds of events can cause. Consider the attacks of September 11, which led to two ground wars, huge (though asymmetric) casualty rates on both sides, and a new era of American foreign policy. Or: the financial collapse of 2008, which saw financial titans like Lehman Brothers evaporating seemingly overnight, and which revealed the fundamental fragility of a financial system that normal people thought was pretty rock solid. If the 2000s taught us anything, it’s that black swans exist—and that we only exacerbate disaster when we respond like ostriches, with our heads in the sand.

Nuclear terrorism is the ultimate black swan: a low-probability, high-consequence event. Americans grew up during the Cold War expecting this kind of disaster, and worse—the holocaust of nuclear war between the US and the Soviets. They prepared for it, too, with the duck and cover drills that every kid of the 50s and 60s still remembers like it was yesterday.

Since the Cold War’s end, however, public fear about nuclear weapons has mostly evaporated. As a result, our preparedness is next to nil, even a decade after 9/11. The general public might think that nuclear weapons are a foreign problem—Iran, say, or North Korea—but not something to worry about inside our own borders. This idea couldn’t be more wrong. Security experts differ from each other when predicting probability for an act of nuclear terrorism on US soil, but none of the estimates are especially comforting, with several former top defense officials speculating about fifty-fifty odds for our current decade.

These kinds of predictions can be easy to write off because nuclear dangers feel too big even to think about. After all, why worry about that sort of thing, because if the Bomb goes off, it’s all over anyway, right? Fortunately, this attitude is only half-right. Nuclear weapons are as bad as we think they are. But, although the Bomb going off means the end of the world as we know it—nothing would ever be the same again—it’s not the end of the world altogether. Most importantly, there are hundreds of thousands of lives at stake in how people react in the direct aftermath.

Here’s why: in a nuclear explosion, even a small one, as we’d expect with a terrorist bomb, nuclear material undergoes a chain reaction to produce a massive release of energy in the form of a shockwave and heat. Anyone caught directly in the explosion—say a half-mile from ground zero—will die instantly, meaning casualties in the tens or even hundreds of thousands, depending. Once the bomb goes off, there is literally nothing to do to protect these people, or save them. And the repercussions will be beyond imagining.

But in the realm of saving lives, there’s also a second wave of casualties to think about, in what bomb experts call the “gray zone.” These are people outside the immediate blast who will be exposed to radioactive fallout. A terrorist bomb would almost certainly be detonated at ground level—in a truck or boat—meaning that the earth and water underneath will be irradiated as fallout and shot skyward in the iconic mushroom cloud. That fallout would then blow wherever the wind takes it, and as it drifts down, would expose anyone in its path to fatal levels of radiation.

Confronted with a seemingly world-ending catastrophe and the imminent arrival of a radioactive cloud of doom, most people’s instincts would be to run. Unfortunately, this is precisely the wrong thing to do. Radiation travels in straight lines through solid matter, and goes through glass and sheet metal—a car, say—like it wasn’t there. But dense material, like packed earth or the lead apron you wear at the dentist when you’re getting X-rays, blocks radiation. This is why the counter-intuitive response will save lives: get underground if you can, or the middle of a big building if you can’t, and stay there until the radiation has dissipated and you know it’s safe to evacuate—likely12-24 hours.

A prepared community could save hundreds of thousands of lives if it reacted the right way—and the information isn’t that complicated. But it really will take a community looking out for each other to save those in the city who can be saved. That’s why we launched KnowShelter, a three-minute online tutorial that’s easily shared within neighborhood and online networks.

We built Know Shelter to be a resource for people of any faith, or none—this isn’t about making sure that one group knows what to do to save its own. The initiative emerges out of a commitment to the common good that is deeply Christian, and we hope that churches and church networks would take the lead in spreading this life-saving news through their communities.