Known as one of the world's most terrifying amusement park rides, the Do-Dodonpa roller coaster in Japan, located near the base of Mount Fuji, has been shut down. The closure comes after several passengers sustained fractured bones while on the ride—though the exact cause of the injuries has officials stumped. The coaster is the fastest-accelerating roller coaster in the world, and the "air-launched" ride also features the globe's largest loop.