TOKYO (NYTIMES) - Looping in view of Mount Fuji, the Do-Dodonpa roller coaster in Japan has been one of the prized fixtures of the Fuji-Q Highland Park since the ride opened in 2001.
One of the world's fastest roller coasters, the Do-Dodonpa can hurtle from a standstill to 180kmh within 1.56 seconds.
But local government officials at the Yamanashi prefecture said last week that the roller coaster would shut down for safety inspections after four passengers reported neck and backbone fractures.
The governor of Yamanashi, Mr Kotaro Nagasaki, criticised the operators of the park, which is about 121km south-west of Tokyo, for failing to add safety precautions or to alert the government sooner.
"I think that if they had reported them earlier and taken appropriate actions, some accidents could have been prevented," Mr Nagasaki said during a news conference last Friday (Aug 20).
Two women and two men in their 30s and 50s suffered fractures of the neck or backbone between December and this month, according to data from the Yamanashi prefecture.
Ms Kimie Konishi, a Fuji-Q Highland spokesman, said the park inspected the tracks and equipment and reviewed the roller coaster's speed after passengers reported their injuries, but did not find any issues. Park officials reported each accident to the police, she said, but did not bring reports directly to the government until the fourth accident, on Aug 2.
"We should have reported earlier," she said in a telephone interview. "Now, we hope the injured people will recover as soon as possible."
Ms Konishi added that all passengers were instructed to maintain contact with head and back rests, but some of the injured passengers told park employees that they might have leaned forward during the ride.
The local police declined to comment to The New York Times.
Fuji-Q Highland will remain closed until government investigators complete their findings.
The odds of amusement park accidents are usually low. The chance of serious injury in a United States amusement park is one in 7.5 million, according to the International Association of Amusement Parks and Attractions.
But accidents are still possible. A woman in Indiana died in June when the force of a roller-coaster ride tore her artery, leading to severe internal blood loss. And an 11-year-old boy was killed in July at a park in Iowa after a raft overturned on a water ride.
In addition to its dizzying rides, Fuji-Q Highland is known for its memorable advertising plea last year when it reopened with new pandemic-related restrictions: "Please scream inside your heart."