One summer, my mother took us to Florida to visit my grandparents and my father stayed home to work. To offset the stress, he exercised. His usual M.O. was to jog until he was exhausted, drink a beer to “recalcitrate” (not a medical term although he used it that way), then swim laps in the pool in our tree-lined suburban backyard. As anyone who has done a medical residency can tell you, your hours are erratic. So he was coming home at dusk and, by the time he finished his jog, it was dark. Our pool was unlit.

I don’t know how he did it, but somehow he managed to squeeze in a movie while we were gone: Jaws. He said later that he didn’t think much about it until he dove into the pool that night.

It was quiet in the pool. And dark.

Very dark.

And, although we lived in land-locked Tucson and our tiny, kidney-shaped pool could not have held a shark the size of Bruce if it had somehow gotten there, Dad got out of the pool and stopped swimming at night.

If you’ve seen Jaws, the events in Twelve Days of Terror may seem familiar to you. A beach resort town. A man goes swimming, something bites off his leg, and he dies. Another man goes swimming, something bites him in half, and he dies. People panic but town officials refuse to shut down the beaches. A swimming child disappears beneath the surface: did he have an epileptic fit? A man dives in to recover his body and something bites him. A few miles away, something chases a child out of the water, ripping the flesh from his leg.

At first, people refuse to believe sharks are involved. Sharks don’t bite people, the scientists tell them. Where they got that from, I don’t know, but it was accepted wisdom then that seems obviously wrong now, like the belief that babies don’t feel pain (which led to a lot of traumatized babies and, I’m guessing, a lot of babies dying of shock) or that doctors didn’t need to wash their hands between patients (which definitely led to a lot of new mothers dying of Puerperal fever) or that dropping test nuclear bombs in rural Nevada wouldn’t endanger people living there (boy, do I have a book for you on this topic).

Eventually even the scientists had to agree that sharks did sometimes attack people – but what was going on here? Why would sharks go on a people binge that summer, when they hadn’t before that?

Theories included a shift in the gulf stream (possible), an taste for human flesh acquired by eating passengers who had been cast into the Atlantic when ships sank during WWI (unlikely), German U-boat induced stress that triggered new shark behaviors (oh, maybe that’s why Orca’s off Spain are torpedoing passing boats…).

Looking back, the reasons seem clear: it was hot, norms had shifted, an increased number of people were swimming. Many people were avoiding swimming pools because of the risk of polio. More people in the ocean means more risk of coming into contact with things that live in the ocean. Like sharks.

Incidentally, the kids weren’t attacked on ocean beaches; they were attacked in Matawan Creek, a tidal creek, which means that the ocean flows up it when the tide comes in and then back down when the tide goes out, like NYC’s East River. And the sharks flow up and down with the tide.

Another theory, widely accepted, was that the killings were all the work of a single shark, a rogue shark. Even today, when there are a series of shark attacks, people want to believe that there’s a shark serial killer out there stalking people, like a tiger who gets too injured to kill real prey so goes for an easy kill: us (book on rogue tigers coming up). But these shark attacks happened over a pretty wide areas. Some happened off ocean beaches, other in the brackish creek.

Sharks were caught and killed. The authorities told people it was safe to go back in the water.

But was it the work of a single killer? It seems unlikely.

I haven’t read the book, Jaws, so I can only comment on the movie. There are some obvious differences between Jaws and the historical events that inspired Jaws: Bruce (the Jaws shark) starts his attacks with a nubile young woman, just the kind to draw people into the theatres. The NJ attacks didn’t include any women: in those days, swimming was more of a man’s activity. Remember, a lot of women were still wearing corsets, and women’s swimsuits were heavy woolen dresses and tights, not the kind of thing to lure a 1970’s movie audience. For many women, swimming was “fanny dunking”, where they waded into the shallows, sunk down so that the water came up just under their chin and, when refreshed, returned to shore. The men who were attacked off the New Jersey ocean beaches were large and particularly athletic, and were swimming for exercise, in the waves beyond the lifeguard-designated area, not in the shallows like Jaws.

But there are echoes of truth in the Jaws movie: people were flocking to the beaches for holiday weekends; local government did worry about discouraging tourism. History shows up in different ways, too: in the movie, during the scene where the shark swims under the bridge, the kids are out in a red canoe. In the N.J. attacks, when one of the men is attacked by the shark, a woman on the beach alerts the lifeguard that a “red canoe” has upset and tossed a man into the water. But the large patch of red she was seeing wasn’t a canoe; it was the man’s blood.

This book is easy to read and makes it easy to picture life in that area in the early 20th century. Although you meet the characters but briefly before they get eaten, you care about them. You feel bad for Lester Stillwell’s family and for the brave tailor who sets out to find his body, for his parent’s sake. You wonder what the heck people were thinking when they carried Lester’s blanket-wrapped remains to his family’s door and placed the tiny blood-soaked bundle in his father’s arms. You share the old sea-captain’s frustration when he sounds the alarm about the shark he sees cruising up Matawan Creek and no one believes him.

I like to re-read this book in the early summer.

Only then, of course, you may not want to go in the water…