Four people were killed after an incident at Dreamworld on Australia's Gold Coast on Tuesday - and while theme parks offer thrills and even the occasional fright, some frighten for all the wrong reasons.
One of the world's first wooden roller coasters - The Derby Racer, which was built in 1911 in Massachusetts - catapulted a man out of his seat and he fell to his death. The ride was demolished in 1936 after it claimed another four lives.
In 2004 a 16-year-old, who was riding a water rollercoaster at Oakwood Theme Park in Wales during a family outing, flew out of her cart and plunged 30 metres to her death as people looked on. CCTV footage showed staff didn't check whether her lap restraint was secure.
A human trebuchet at Middlemoor Water Park in England, which catapulted people into a big safety net, killed a 19-year-old man in 2002. He missed the net by a few metres and later died from his injuries.
A 14-year-old lost her feet in 2007 at the Six Flags Kentucky Kingdom Amusement Park, when a free-fall thrill ride malfunctioned. The girl was on the Superman ride, but the cord wrapped around her feet as the ride took her 53 metres into the sky - and when the ride dropped her at 80km/h, it cut off her feet.
One of the worst theme park accidents, though, happened on the Haunted Castle ride in New Jersey In 1984 - the ride suddenly burst into flames, and 18 people got trapped in the house, where they died from asphyxiation.
And Auckland's own Rainbows End has also had accidents - in 2015 a family got stuck at the top of the rollercoaster when it overheated.
While they escaped alive, a 21-year-old wasn't so lucky - in 2008 the man was instantly killed when he became trapped in a children's ride while he was cleaning it.