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.

The park’s spokeswoman said in a statement that “a limited portion” of the park would reopen Wednesday.

Each rider on the Verruckt must be at least 54 inches tall, and the group’s weight is limited to a total of 400 to 550 pounds. Caleb was seated with two women unrelated to him and who sustained minor facial injuries.

Police were investigating the death as a criminal case although police spokesman Cameron Morgan said Tuesday that designation did not mean they suspect foul play.

Caleb’s parents — Republican state Rep. Scott Schwab and his wife, Michele — have requested privacy and have not spoken publicly since the death of Caleb, whose funeral is Friday.

Verruckt’s 2014 opening repeatedly was delayed, though the operators didn’t explain why. Two media sneak preview days in 2014 were canceled because of problems with a conveyor system that hauls 100-pound rafts to the top of the slide.

Kansas statutes governing amusement rides don’t specifically mention waterslides. State law leaves it to the Kansas Department of Labor to adopt rules and regulations relating to certification and inspection of rides, adding that a permanent amusement ride must be scrutinized at least once a year by “a qualified inspector.”

Regulations require only that owners of permanent amusement rides retain records for a year and rides are randomly selected quarterly for a records audit.

Documents released Tuesday by the state department showed that in June 2012, a records audit found that the park was not maintaining records of testing for current and previous years. The report said that instead of such testing, “visual inspections are conducted annually and daily.” There was no record of a state response, and the audit was marked “pass.”

There were no indications of further records audits, and department officials did not immediately answer questions about why that was so.

The state requested documentation from Schlitterbahn “to ensure all safety requirements have been followed.” Department officials didn’t immediately provide additional details.

Associated Press writers Jim Suhr, Bill Draper and Margaret Stafford in Kansas City and John Hanna in Topeka contributed to this report.