They were all the rage in the late 1950s—fallout shelters you could build in your basement or backyard. Now viewed with comic tolerance, the shelters were a response to a series of very real threats, starting with the Korean War and the execution of the Rosenbergs for spying and culminating in launch of Sputnik in 1957. In between, the United States and the Soviet Union traded nuclear-bomb tests tit for tat. America and Canada built the Distant Early Warning Line of radar stations across the Arctic. The U.S. staged mass evacuations of its largest cities. And children huddled under their desks in duck-and-cover drills.

The threats were anything but comic.

In June 1959, the Office of Civil and Defense Mobilization published a 32-page pamphlet called The Family Fallout Shelter. The text was sobering:

Let us take a hard look at the facts. In an atomic war, blast, heat, and initial radiation could kill millions close to ground zero of nuclear bursts. Many more millions—everybody else—could be threatened by radioactive fallout. But most of these could be saved. The purpose of this booklet is to show how to escape death from fallout.

The booklet contained building plans for several types of shelters: basement concrete block, above-ground double-wall, pre-shaped corrugated metal, and underground. (Harry Goucher used similar plans for his backyard shelter in the novel Distant Early Warning. Imagine you’re a young mother like Georgia Andersen watching him build a four-person bunker and wondering where the rest of your neighbors will shelter.)

The booklet listed equipment and supplies for a prolonged stay and advised readers to “be prepared to make it your home for 14 days or longer.” Four to six people in a shelter with a hand-crank air pump and a bucket for a toilet. How long do you think most of us would last?

Jeff Widmer’s latest book is Distant Early Warning, a novel of the Cold War.