As Americans prepared to celebrate the Fourth of July holiday weekend in 1916, the aptly named resort town of Beach Haven, New Jersey, promised a sanctuary from worries about the war raging in Europe and the polio epidemic sweeping through New York City. Seeking refuge from the sweltering heat gripping his hometown of Philadelphia, Charles Vansant stepped out of his beachfront hotel to take a quick dip in the Atlantic Ocean before dinner on July 1, 1916.

The athletic 25-year-old waded into the shallow surf and swam out from shore with a paddling Chesapeake Bay retriever at his side when a dark fin suddenly sliced through the 3-and-1/2 foot deep water. The sea creature clamped onto Vansant’s left leg and refused to let go. The swimmer unleashed a morbid scream as the ocean’s white breakers turned red. A human chain tried to tug him to safety, but the animal did not unclench its jaws until its belly scraped on the pebbles in the shallow waters near shore. The rescuers carried the badly injured Vansant into the lobby of the luxurious Engleside Hotel where he bled to death.

The attending physician recorded a remarkable cause of death—a shark bite. While swimming in the ocean was still a nascent American pastime in the early 1900s, shark attacks along the coast of New Jersey were unheard of. Many scientists believed sharks to be shy, just another fish that swam offshore and posed no threat to swimmers, and not powerful enough to maul a human. Stories of shark attacks told by ancient mariners were often dismissed as salty tales akin to stories of sea serpents. “Bathers Need Have No Fear of Sharks,” declared a headline in the Philadelphia Public Ledger in which experts dismissed the attack on Vansant as a freak incident in which the shark was actually trying to attack the dog swimming near the victim.

Five days later, however, terror once again struck from the sea 45 miles north of Beach Haven as Charles Bruder swam out beyond the breakers of Spring Lake, New Jersey. The 27-year-old Swiss bellboy captain at the Essex & Sussex Hotel was taking his regular lunchtime swim when a “man-eater” struck 130 yards from shore and bit off his left leg above the knee and the right leg just below the knee. Lifeguards pulled the maimed Bruder to shore as women fainted at the sight. There was nothing that could be done to save him.

While an assistant curator at New York’s American Museum of Natural History who examined Bruder’s body declared the mutilation the work of a killer whale, others clung to the belief that a giant tuna or great sea turtle must have been the culprit. Some conspiracy theorists believed the attack was the work of a shark—that is a shark trained by the Germans to follow their U-Boats and strike American bathers.

Protective nets were now installed at beaches along the Jersey Shore as boats patrolled the ocean waters, but they proved useless in preventing the next attack, which occurred 25 miles north of Spring Lake on July 12. As the sun beat down on a 96-degree day, Lester Stillwell frolicked with other boys in a popular swimming hole along Matawan Creek. A sympathetic foreman at the basket-weaving factory where the frail 11-year-old worked had taken pity on his overheated employees and given them the afternoon off to cool down. Lester found relief in the brackish water of the placid creek more than a mile inland from where it emptied into Raritan Bay. As the boy floated on his back, a shadow suddenly emerged from the depths. A shark grabbed him by the stomach and pulled him under the water. He briefly surfaced long enough to utter a horrific scream before the shark once again took him under.

The rest of the terrified boys ran down Matawan’s Main Street yelling for help. A local tailor, 24-year-old Stanley Fisher, joined the townspeople rushing to the scene and from a rowboat probed the murky waters with a pole. Finding no signs of life, it eventually became clear that the mission had switched from rescue to recovery. When Fisher spotted Lester’s body as the boy’s parents watched from the banks, he dove into the creek, even knowing that a killer shark lurked nearby. As Fisher retrieved the lifeless body, the shark reappeared and tore into his right leg. Dragged to shore by his neighbors who desperately attempted to bandage the wound, Fisher passed away hours later.

Thirty minutes after the attack on Fisher, a shark bit the leg of 12-year-old Joseph Dunn near the mouth of Matawan Creek, but the boy managed to survive. The killer fish became public enemy number one with bounty notices promising a $100 reward “to the person or persons killing the shark believed to be in Matawan Creek.” Revenge-minded mobs wielding spears and pitchforks descended upon the banks of the creek as flotillas of shark hunters took to the water. Posses fired shotguns and tossed sticks of dynamite at any movement they saw in the creek’s muddy waters.

Telegrams and letters poured into the White House from panicked Americans urging the federal government to do something to stop the rogue man-eater. Two days after the attack in Matawan Creek, President Woodrow Wilson convened a cabinet meeting to discuss “the shark horror gripping the New Jersey Coast.” He tasked the treasury secretary to lead a “war on sharks” that included efforts by U.S. Coast Guard cutters and the Bureau of Fisheries to “rout the sea terrors.”

That same morning in a small motorboat off the coast of South Amboy, New Jersey, shark hunter Michael Schleisser spotted a black tail fin in the dragnet he had cast in Raritan Bay and struck the shark repeatedly on the head with a broken oar handle until it no longer moved. Back on land, Schleisser gutted the shark and human bones were reportedly found inside but never conclusively identified. Whether that particular shark was indeed the man-eater was not proven, but no further attacks occurred in New Jersey the rest of the summer.

The relationship between Americans and sharks, however, would never be the same again. No longer seen as benign, sharks were man-eating predators to be feared. Even the most skeptical scientists, as the New York Times reported, “no longer doubted that big fish attack men.” Although author Peter Benchley told the New York Times that the 1916 attacks in New Jersey did not serve as the inspiration for his novel “Jaws,” which was adapted into the 1975 blockbuster film, the parallels of a man-eating shark terrorizing a summer tourist resort are unmistakable.