Footage circulating online show the "360 Degrees" ride breaking in half, with the circular carousel crashing down from a height of several meters.
The Saudi-owned Al Arabiya TV channel reported 23 injured, four of them seriously, in the accident on July 30.
The amusement park in Taif, in south-west Saudi Arabia, has been closed and an investigation is under way, Al Arabiya added.
Saudi Arabia has been building multiple leisure and entertainment attractions as the long-cloistered desert country seeks to diversify its oil-reliant economy.
Among its so-called giga-projects is Qiddiya near Riyadh, billed as an "entertainment city" of theme parks and a motorsports racetrack.