KANSAS CITY, Kan. — A 10-year-old boy who was killed at a Kansas water park while riding on a 17-story waterslide was decapitated, a source told The Associated Press Wednesday.

A person who is familiar with the investigation but is not authorized to speak about it said Caleb Schwab was decapitated Sunday on the “Verruckt” ride at the Schlitterbahn WaterPark in Kansas City, Kansas.

Caleb, the son of a Kansas lawmaker, was in a raft with two adults who were not related to him when he was killed on the 168-foot tall ride, which is billed as the tallest in the world. The other two people were treated for facial injuries.

At least two people who rode in the last year on “Verruckt” — German for “insane” — say nylon shoulder straps came loose during the raft ride.

It’s unclear whether the straps played any role in Caleb’s death. Police and Schlitterbahn have not provided any other details of Caleb’s death.

A spokeswoman for the waterpark on Wednesday declined to discuss the circumstances of the boy’s death.

The park said Tuesday that the ride would be closed for the remainder of the season.

On the 2-year-old waterslide certified by Guinness World Records as the world’s tallest, riders sit in multi-person rafts that begin with the steep drop, followed by a surge up a second hill before a 50-foot descent to a finishing pool. Along the way, riders clutch ropes along the inside of the raft.

Riders are harnessed in with two nylon seatbelt-like straps — one that crosses the rider’s lap, the other stretching diagonally like a car shoulder seatbelt. Each strap is held in place by long Velcro-style straps, not by buckles.

Ken Martin, a Richmond, Virginia-based amusement park safety consultant, questioned whether the straps were appropriate for what he called “nothing more than a roller coaster with water.”

In early tests, rafts carrying sandbags flew off the slide, prompting engineers to tear down half of the ride and reconfigure some angles. A promotional video about building the slide includes footage of two men riding a raft down a half-size test model and going slightly airborne as it crests the top of the first big hill.

“I think they designed this ride, and they figured since stuff was flying out, we better do something to keep people from flying out,” he said. “I think we have a serious issue with the restraint system. Period.”

Although he has not seen or ridden Verruckt, Martin said a more solid restraint system that fits over the body — similar to those used in roller coasters — may have been better.

Jon Rust, a professor of textile engineering at North Carolina State University, said the material used on the straps, commonly called hook and loop, isn’t designed to keep a person in the seat. It also can get old and degrade with use.

“It’s got to be used in a safe manner, and that doesn’t include stopping someone’s fall or preventing someone’s ejection,” Rust said.

Paul Oberhauser told local television station KCTV that his shoulder restraint “busted loose” on his Verruckt raft July 26. The Nebraska man said he “just held on,” and a video shot by his wife shows the strap loose at the ride’s end. Oberhauser said he reported the matter to park workers.

Kenneth Conrad told WDAF-TV that during his trip down the waterslide last year with a friend, the friend’s shoulder strap came “completely off.” Conrad’s wife snapped a photo at the end of the ride showing the strap missing, and Conrad didn’t file a complaint with the park.