SummerFun Under Scrutiny 여름을 철저한 조사 아래 즐겨라. When Summer hits, it’s amusement park season. ... In 2011, Japan opened what is claimed to be the world’s steepest roller coaster. ... Many times in accidents such as these, these cause is not clear. 이것과 같은 사고가 많았지만 원인은 명확하지 않았다.