A disabled 36-year-old man fell 32 feet (10m) from the Gerstlauer Euro-Fighter roller coaster and was transported to hospital with serious injuries. The double amputee was allowed to ride even though he had no legs and the coaster is outfitted with only lap bar restraints. Source (in Spanish)
Accidents
Theme parks and roller coasters are statistically very, very, very safe. Out of the millions of people who ride the thousands of rides every year, there are only a small handful of incidents. You are statistically more likely to be involved in an accident driving to an amusement park than having one at a park. The rarity of accidents is one reason why the media report them, similar to plane crashes.
Every important element of a ride is inspected on a regular basis and every ride is tested every day without passengers before it opens. A ride might not open, or a safety system might activate, if there is an imperfection. For theme parks to operate, they must obtain insurance and one stipulation is their rides are frequently inspected and signed off by a strict Health & Safety governing body. Every theme park does what they can to prevent accidents because the negative press would be bad for business.
Having said all that, theme park accidents still happen…
Winjas, Phantasialand, Brühl, North Rhine-Westphalia, Germany
A 58-year-old park technician was pinned between two of the spinning coaster cars during routine inspection and succumbed to head injuries. Source (in German)
Skyfall, La Feria, San Juan, Puerto Rico
A 59-year-old carnival worker died, when he was struck by the Kamikaze pendulum ride he was operating. The employee with over 30 years experience in the industry, apparently slipped while trying to retrieve an object a passenger dropped. Source
Mt. Olympus, Wisconsin Dells, Wisconsin, USA
A 16-year-old boy was killed when he fell about 35 feet (10.6m) while attempting to sled down one of the closed off snow-covered water slides at Mt. Olympus Water & Theme Park. Source
Thunder River Rapids, Dreamworld, Queensland, Australia
Four people, one woman and three men aged 32-42 years old, were killed when a river rapids raft flipped over on the loading platform. When an empty raft got stuck in the station, a conveyor belt malfunction forced the returning raft onto the one ahead and tipped it over. Source
Top Spin, Jinnah Amusement Park, Rawalpindi, Pakistan
One man died and nearly a dozen riders were injured when an entire row of harnesses came open on a locally built Top Spin style ride. Source
Rollo Coaster, Idlewild & Soakzone, Pennsylvania, USA
A three-year-old boy suffered head trauma when he was ejected from the wooden coaster on the last curve and fell 12 feet (3.7m) to the ground. Source
Ferris Wheel, Greene County Fair, Tennessee, USA
Three girls, ages 6, 10 and 16, were injured when their gondola overturned and they fell 30 feet (9m) to the ground. The youngest suffered a traumatic brain injury. Source
Verruckt, Schlitterbahn Water Park, Kansas, USA
A 10-year-old boy died when he was decapitated after being ejected from his raft on the world’s tallest water slide. Source
SuperShot, Frederick County Fair, Virginia, USA
A 47-year-old woman suffered several injuries when she fell 40 feet (12m) to the ground after her seat detached when a cable snapped. Source