More from the wiki article:

A real recipe for success from the very start:

The water slide was conceived on the spur of the moment by Henry, after a team from Travel Channel's Xtreme Waterparks asked at a trade show what he was working on. After initial attempts to pitch the idea to vendors at the show failed, Henry decided to build the slide himself, enlisting John Schooley as the ride's lead designer. Henry had described the new ride to the Travel Channel crew as a "speed blaster", a term he had likewise improvised. He and Schooley knew that Schlitterbahn had to live up to the hype Henry had created and design something previously unheard of. Basically we were crazy enough to try anything, Schooley later recalled.

Henry pressed his design team to complete the ride at a faster pace than usual; many of those involved worked almost around the clock. Calculations that were normally allotted three to six months instead had five weeks to be completed. As they began testing, rafts kept going airborne on the ride's large bottom hump.

Who could have seen this coming?

An unnamed lifeguard at the park told Esquire in 2019 that he saw some of the later tests, which the park primarily did after it had closed for the day, with only select employees – usually those who had been with the company for the longest – allowed to watch. In his case, he saw the Xtreme Waterparks crew ride the ride. "The only time I saw the slide run successfully was on the Travel Channel episode,[a] but I wouldn't even call that successful", he recalled, since the raft in that case got stuck on the second hump. Sandbags on the raft frequently went airborne at that point as well; some viral videos of this leaked out. "I told my friends and family it was only a matter of time until someone died on Verrückt", the lifeguard said.

A safety consultant hired by the park shortly before Verrückt's scheduled opening told Henry it was unfinished and unsafe. When complete, he recommended that only riders 16 and over be allowed on the ride. Henry, who had no formal training in engineering, decided 14 was better. Right before the opening, however, he dropped any age limit.

The same survivorship bias that pervades so much of the US (now super obvious with covid spreading:

The riders who had seen the videos of 110-pound (50 kg) sandbags flying off the rafts went on anyway—one local judge told Esquire later that she rode the water slide ten times that day, and an employee who had loaded the sandbags during testing said he went down twenty times over its first two days. "That should tell you something about how I felt about it", he said.

Being a well-studied psychological phenomenon, it's not uniquely American, but definitely something that people should be learning about.

There's also this terrifying stuff when you go to a water park to have a good time and be mostly unconcerned with your safety (don't get drunk and don't run on the pavement and you should be just fine):

However, at least thirteen riders suffered non-fatal injuries, such as concussions or slipped and herniated discs – many of which had longterm effects – after either hitting the netting or being thrown into it. After a Missouri man thrown from the raft suffered facial injuries in June 2016, the park's operations manager allegedly attempted to cover up the incident, telling lifeguards what to write in their reports; it is believed that was not the only accident where this happened.

Even some riders who were uninjured were unnerved by Verrückt. A Kansas City man who had made a point of going down it due to favorable experiences with the Texas Schlitterbahn parks recalled having to grab the raft's auxiliary straps when the Velcro ones holding him came loose after the first drop; he was thankful that his son had used the weight limit as an excuse not to ride A local woman whose boyfriend held her in the raft likewise noted to Esquire that the netting and hoops on the lower hump showed signs of many instances where people had collided with it.