A support beam fell onto the track of the Reverchon Wild Mouse spinning coaster forcing an emergency stop and evacuation of the ride. No guests were injured in the incident. Source
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…
Xtreme, La Aurora Funfair, Daule Canton, Ecuador
Ten people were injured, six critically, when an arm detached from the swinging pendulum ride sending riders crashing to the ground. Source (with video)
Remolino-Schlittenfahrt, Fair, Pachuca, Hidalgo, Mexico
Four children and five adults were injured when the cars on the Matterhorn/Himalaya ride derailed, causing the attraction to collapse. Source
Olympia Looping, Oktoberfest, Munich, Germany
A 20-year-old male employee died when the Schwarzkopf multi-looping coaster hit him during test runs a few days before the world-famous festival was due to begin. Source
Kangaroo, Feria de Bornos, Cádiz, Murcia, Spain
Three girls between the ages of 7-10 were seriously injured when one of the gondolas broke completely off the Safeco Saltamontes/Jump N Smile fair ride. Source (in Spanish)
Swimming Pool, Discovery Cove, Orlando, Florida
A man in his 60s died after being found unconscious in a pool at the marine-themed park. The man was rushed to a hospital, where he was later pronounced dead. Source
Crazy Clown, Kirmes, Alkmaar, Netherlands
A 4-year-old boy was treated in hospital for injuries suffered when he fell about 10 feet (3 m) to the ground from the funfair’s wacky worm roller coaster. Source (in Dutch)
Ferris Wheel, Potosina Fair, San Luis Potosí, Mexico
A 39-year-old woman died after falling between 65 to 82 feet (20-25 m) from the top of the Ferris Wheel. Source
Wacky Worm, Alem Paraíba, Minas Gerais, Brazil
A 37-year-old woman suffered serious injuries after getting thrown out of the kiddie roller coaster. Source
Crazy Dance, Dino’s Luna Park, Pefkochori, Greece
A 19-year-old man died after being ejected from a locally built copy of a Break Dance ride. Source