Eyewitness describes horrific moment 10-year-old boy was decapitated by 'world's tallest waterslide'

Warning: This article contains graphic descriptions which some readers may find distressing.

An eyewitness has spoken out after seeing a 10-year-old boy be decapitated on the 'world's tallest waterslide'.

In 2016, Caleb Schwab and his family visited the 'world's best waterpark,' Schlitterbahn Waterpark in Kansas City and the 10-year-old went on the 170-foot-tall Verruckt water slide.

Along with two other riders, Caleb - son of state legislator Scott Schwab and Michele Schwab - climbed 264 steps to get to the top of the slide which had been touted as the 'world's tallest' when it first opened in 2014.

He then climbed aboard to plummet 17 storeys down before shooting over a 55-foot-tall crest.

The chute was covered with netting to prevent sliders from falling off the slide and was supported by metal poles.

However, Caleb ended up being thrown off the raft due to the speed and motion of the ride and made contact with one of the metal poles which decapitated him, his death ruled as a 'fatal neck injury at the end of the ride,' as per Kansas City Police.

And an eyewitness later spoke out about the horrifying tragedy.

The tragedy occurred at Schlitterbahn Waterpark (Erich Schlegel/Getty Images)

An eyewitness told Texas Monthly: "It was as horrible a moment as you could imagine.

"A nightmare beyond comprehension. I can’t begin to describe it."

A grand jury later filed charges of second-degree murder against Schlitterbahn co-owner Jeff Henry and senior designer John Schooley.

However, the charges were dismissed and in 2017, Caleb's family settled the case and received nearly $20 million from the companies involved.

At the time of Caleb's death, Schlitterbahn told ABC News: "[The park has] never experienced this kind of devastating event [in its 50 years of operation].

"The safety of our staff and our guests is our top priority. We are parents and grandparents ourselves, and many of us had ridden Verruckt with our own children and grandchildren over the years it operated.

The slide was touted as the world's tallest (ABC News)

"At Schlitterbahn, we take safety very seriously. We support effective guidelines that increase guest and staff safety."

The ride was closed in 2016 following the incident and by September 2018, the whole water park had closed and it was dismantled two months later.

After Caleb's passing, it became a law for state inspectors to check over attractions at amusement parks.

If you have experienced a bereavement and would like to speak with someone in confidence, contact The Compassionate Friends on (877) 969-0010.