An enclosed water slide with a complete loop where customers ended up with bloody noses. A wheeled ride with no brakes that shot down a concrete-and-fiberglass track. A freshwater pool with giant waves that required lifeguards to rescue over two dozen people a day. New Jersey’s Action Park, which quickly became known as “Accident Park”, had it all. It was arguably America’s most dangerous water park.

Opened in Vernon, New Jersey, in 1978, Action Park was one of the first modern water parks in the United States. Founder and CEO Gene Mulvihill’s philosophy was that amusement park visitors should be in control of their experience, envisioning a park where patrons managed the rides—including how fast and how high they went. And that’s exactly what he created at Action Park.

One extreme example was the park’s Alpine Slide, which has been described by an old Action Park regular as, “essentially a giant track to rip people’s skin off that was disguised as a kid’s ride.” The slide featured a long, cement-and-fiberglass-filled track that visitors rode down in a wheeled device. But first, park goers would take a ski lift to the summit, where they were greeted by photographs of injured children, accompanied by a warning for riders to keep their arms inside their device.

In theory, each rider was in charge of their own speed, but the devices were almost always broken. Some had no brakes, which meant there was no slowing down as they would zoom down the concrete slide. Others had the brakes locked on, causing the rider to crawl down the slide, inevitably being hit in the back by another, speedier, rider. The park saw its first fatality on the Alpine Slide, when a 19-year-old rode off the track and hit his head. According to New Jersey’s records, there were at least 26 other serious head injuries and 14 fractures attributed to the Alpine Slide.

One of the park’s most notable attractions was the Tidal Wave Pool, one of the first to open in the United States, which quickly became one of the most dangerous rides at the park. Nicknamed, “The Grave Pool,” it was filled with fresh water, not sea water, which made patrons less buoyant and left strong swimmers and non-swimmers alike literally in over their heads as waves that could reach 40 inches at high blast. The 12 lifeguards on duty rescued, on average, 30 people a day on high-traffic weekends.

But the most infamous of the rides at Action Park was the Cannonball Loop—an enclosed waterslide with a complete vertical loop. According to one urban legend, when park owners sent a dummy doll on a test run of the ride, it came back with no head. Gene Mulvihill offered his employees $100 to test out new rides, including the Cannonball Loop, and despite employees winding up with bloody noses and bruises, he opened the ride. One person even remembers hearing that a patron got stuck at the top of the loop, causing the park to build a hatch to aid in future rescues.

Just a month after it opened, and after countless injuries were reported, it was shut down by the Advisory Board on Carnival Amusement Ride Safety. Today, Mulvihill’s son admits that they “never quite perfected that one.” But, he remains proud of his father for taking a risk with the ride in the first place, “My father, if he could find a guy with a crazy idea for a ride, he’d hire the guy, even if he never built it before.”

It wasn’t just the thrill of the dangerous rides that kept kids coming back, summer after summer. It was also the park’s “anything goes,” choose-your-own-adventure mentality. Then-underage visitors remember being able to drink beer freely and run through the park without a care—or much in the way of adult supervision. In fact, doctors who treated the many injuries incurred at the park noted most people were intoxicated, regardless of their age. The employees (including Mulvihill’s own five children) were often teenagers themselves, having as good of a time as the patrons.

Action Park was finally closed in 1996. By then, the park was responsible for six fatalities, including three drownings in the Tidal Wave Pool and the death of a 27-year-old man who was electrocuted on the Kayak Experience when his boat tipped over and he came into contact with water that had a loose wire touching it.

In 2010, Mulvihill led a committee to buy the park back. It reopened in 2014 with a new name, Mountain Creek Waterpark, and now advertises its trained lifeguard staff and stringent, up-to-standards safety features. But for a generation of kids from the Tri-State area, nothing will replace the dangerous thrills of a hot summer day at Action Park.