An eight-year-old girl has died after being thrown from a ride at the Royal Adelaide Show.

The girl was unconscious after falling from the Airmaxx 360 ride just before 12:30pm ACST on Friday.

She was rushed to the Adelaide Women's and Children's Hospital at North Adelaide from the showgrounds at Wayville.

SafeWork SA later confirmed that she had died.

Royal Agricultural & Horticultural Society of South Australia president John Rothwell said the organisation would assist police and Safework SA with an investigation.

"The ride, Airmaxx 360, was a new ride for the Royal Adelaide Show this year," he said.

"However, it operated at both the Sydney Royal Easter Show, and the Brisbane show only a few weeks ago without incident.

"All rides at the show must pass a national compliance audit prior to the show opening and undergo daily checks by operators.

John Rothwell said the Air Maxx 360 ride was a new ride for the Royal Adelaide Show this year. ( ABC News )

"This will be the subject of a thorough investigation and our heartfelt condolences are with the family."

The Airmaxx 360 will be closed for the remainder of the show, but the rest of the amusements are open.

Mr Rothwell said members of the society were "extremely upset" but that SA led the nation in terms of ride safety over the years.

In 2006, two teenage girls suffered cuts and bruises when their carriage on the Twin Flip ride crashed into a metal deck.

The operator, TPA Shows, was fined $36,000 after the Industrial Relations Court found it did not have sufficient technical expertise to control the machine.

Audit of Airmaxx 360 showed no 'obvious' compliance breaches

SafeWork SA executive director Brian Russell said an audit of the Airmaxx 360 had shown no obvious compliance breaches.

He said there were more than 60 rides at the show and they were all subject to the same inspection.

"There were no complaints prior to this, and the process we go through provides the confidence that each device must be inspected by a qualified engineer," Mr Russell said.

"All critical items have to be regularly inspected.

Earlier, police cordoned off the scene and Attorney-General John Rau said the ride was shut down until Safework SA had completed its investigation.

"As a parent I am obviously very concerned that we should have a position where one of these rides at the Royal Adelaide Show is involved in a serious incident," Mr Rau said.

"We don't know any more about it at the present time but it's under investigation."

There was no age limit on the ride but height restrictions did apply.

SA Police chief inspector Dennis Lock appealed for witnesses and anyone who had ridden the Airmaxx 360 to talk to police.

He said the ride operators were being spoken to by Sturt Crime Investigation Branch, but it would be up to a coroner to decide whether it would be treated as a crime or not.