A 3-year-old girl was airlifted to hospital after she suddenly ran onto the Panoramabahn station tracks as a train approached and grazed her. The child was in the company of her parents, which is required for anyone under 6 years of age. Source (in German).
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…
Rebel Coaster, Royal Melbourne Show, Australia
A 26-year-old woman was transported to hospital in a critical condition suffering from injuries to her arms, legs, back, neck and face after being struck by the Zyklon/Galaxy model roller coaster by Czech manufacturer Ride Technic. The incident occurred when she walked onto the coaster track to retrieve her mobile phone, was struck by the train and thrown several meters into the air before landing on the ground. Source
La Isla, Allou Fun Park, Attica, Greece
Four people were injured, two critically, when they were ejected from the log flume ride when a momentary drop in the water level inside the trench caused their boat to suddenly stop. Source
Drop Tower, Phase 8 Fair, Mohali, Punjab, India
At least 10 people, including five children, were critically injured after the transportable rotating drop tower came crashing 50 feet (15m) to the ground. Source
Rocket, Southport Pleasureland, Merseyside, UK
Poogee Penguins Spin Out Coaster, Santa’s Village, NH
A 51-year-old ride operator was seriously injured after falling 6-8 feet (1.8-2.5m) to the ground from the SBF Visa Group spinning coaster’s platform. Source
El Toro, Six Flags Great Adventure, Jackson, New Jersey
Thirteen people were injured, five of which were taken to hospital, when the roller coaster train suddenly jarred, as though it had hit a pot-hole, just before returning to the station. The attraction closed for the remainder of the season. Source
Train, Land of Make Believe, Hope Township, New Jersey
A 2-year-old child was seriously injured and airlifted to hospital in critical condition after being struck by the park’s train. Source
Feuerdrache, Legoland Deutschland, Günzburg, Germany
Europe Flyer, Venray Kermis, Netherlands
Eight people sustained minor injuries while riding the swing carousel at the street fair when they struck tree branches. Occupants may have grabbed the branches while riding, causing tension straps that were holding the branches away from the ride to loosen. Source (in Dutch)