The world's fastest rollercoaster has closed after riders reportedly broke their bones due to its crushing speed.
The Do-Dodonpa, at the Fuji-Q Highland theme park, Yamanashi Prefecture, in Japan, closed earlier this month after four people reportedly suffered injuries between December 2020 and August this year.
However, a statement from the park read: "Currently, the causal relationship between injuries and amusement machines has not yet been confirmed."
Yamanashi Prefecture, located around 75 miles southwest of Tokyo, said in a news conference that the four injured riders ranged in age from their 30s to 50s and suffered a fractured neck, chest, and back bones, Japanese newspaper The Asahi Shimbun reports.
The rollercoaster opened in 2001 before undergoing a major renovation in 2017.
It became known as one of the fastest coasters in the world, as the ride’s cars are mechanically propelled to accelerate to about 111 mph in approximately 1.56 seconds.
The only incident before 2020 December that raised concerns occurred on 15 May 2007, when a 37-year-old man sustained a minor injury after a plastic cover at the front of the train came loose and hit his right knee.
Naoya Miyasato, an Nihon University architecture professor who specialises in coaster designs, told Vice in an interview that the injuries could possibly be the outcome of rapid acceleration.
He said: "If a rider can’t withstand the acceleration, then they sustain an injury, which could be what’s happening here.
"If they detected no serious concerns with the actual ride, then it could be the way people were sitting.
'But if a person was sitting incorrectly, say with space between their backs and their seat, it’s the responsibility of the park employees to check their seating position."
The ride closed on August 12 2021, pending an inspection.