Theme Park Attraction Malfunctions, Killing 4 Who Were Thrown From or Trapped Under Ride

Two men, ages 35 and 32, and two women, ages 42 and 38, were pronounced dead by police after the incident.

Four people were killed at Australia’s largest theme park Tuesday when a “family friendly” ride malfunctioned, ejecting two and trapping two others under a conveyor belt, authorities said.

Two men, ages 35 and 32, and two women, ages 42 and 38, were pronounced dead by police after the incident on the Thunder River Rapids Ride at the Dreamworld theme park in Queensland at about 2 p.m. local time Tuesday, CNN reported.

"One of the rides had sustained some sort of malfunction, causing two people to be ejected from a ride, another two people were caught inside the ride," Gavin Fuller, acting senior operations supervisor for Queensland Ambulance Service, told CNN.

The ride involves floating down a river filled with artificial rapids. The water was drained by emergency services during rescue efforts, The Guardian reported.

All four victims had sustained injuries so severe that they could not be saved, Fuller said, noting that "a number" of staff from the ambulance service had been "deeply affected by this terrible accident."

Read: Girl, 11, Who Was Scalped on Carnival Ride Finally Gets to Go Home

It was not immediately clear if the four victims were known to each other. An investigation is underway and police are trying to contact the victims' families, Inspector Tod Reid of the Queensland Police told reporters.

Dreamworld is closed until further notice as a mark of respect for the victims and their families, according to Alan Shedden, company secretary for Ardent Leisure, which owns the theme park.

“Dreamworld’s focus and priority is with the families of those involved in this tragedy,” Shedden said in a statement.

The theme park is working closely with police and emergency services to establish the facts around the incident, Craig Davidson, the park’s CEO, said at a press conference.

“We are deeply shocked and saddened by today’s accident; our hearts and thoughts go out to the families involved and their loved ones,” Dreamworld tweeted.

The deadly accident is the latest of several to occur at a place usually thought of as fun for the whole family.

An 11-year-old girl in May was left fighting for her life after she was scalped by a carnival ride in Nebraska.

Elizabeth ‘Lulu’ Gilreath finally returned home after a month in the hospital, where she spent time in pediatric intensive care and underwent several surgeries to reattach her severed scalp. She will likely face more medical hurdles as time goes on.

In August, a 10-year-old boy suffered a fatal neck injury while riding a Kansas water slide dubbed the tallest on Earth.

Read: Lawmaker's Son, 10, Suffered 'Fatal Neck Injury' On World's Tallest Water Slide, Cops Reveal

Caleb Schwab was killed while riding in a raft that dropped 168 feet, authorities said.

Though officials would only note that the boy incurred a fatal injury “at the end of the ride,” witnesses at the time told reporters the boy appeared to have been decapitated.

And in September, a Memphis man suffered a fatal heart attack during a trip to Disney World in Orlando, Florida, authorities said.

After Ralph Lyles and his grandson rode Star Tours: The Adventures Continue, the Disney-lover told his grandson that he wasn’t feeling well and needed a cup of ice, WMC reported. Lyles reportedly collapsed and died of a heart attack moments later.

Lyles’ family said that he was taking medication for a heart problem, according to the news site. A Disney World representative confirmed the ride has signs warning visitors not to ride if they have a pre-existing heart condition.

“Disney is the one place were dreams come true,” Shaianne Lyles, his granddaughter, said. “How can I feel bad when he died in the happiest place in his mind, the happiest place on earth?”

Watch: Six Children Injured By Electric Shocks On Amusement Park Ride: Cops