At least 18 people were injured Saturday when a packed amusement ride collapsed at a theme park in southern Spain, officials said. Many of the casualties were local children on a school trip to the park near Seville. A woman and a girl were transported to hospital by helicopter. Four of the injured were said to be in a serious condition. The carousel, known as "The flyer" collapsed shortly after the ride began. The reason for the accident was not immediately clear but authorities are investigating.