The roller coaster car that derailed at the Expoland amusement park and killed a young woman apparently suffered its broken axle in the first half of the ride's 2,340-meter-long course, contrary to what the park operator claimed, investigative sources said Tuesday.
Part of the broken axle was found on the ground under the rail about 170 meters from the starting point, north of the spot cited by the operator, the sources said.
Investigators have also found scratch marks on the rail running for several meters at a point closer to the coaster's starting point than the operator said earlier.
This indicates one of the axles on the second car of the six-car roller coaster broke at an earlier stage than suspected, the sources said.
Yoshino Kogawara, 19, was killed Saturday when the derailed car hit a guardrail, and 19 others on the Fujin Raijin II standup roller coaster were injured.
The sources said the coaster might have traveled more than 500 meters in an unstable manner after the axle broke in the first half of the course.
Investigators are still searching for more axle fragments.
In Tokyo, Tetsuzo Fuyushiba, minister of land, infrastructure and transport, told reporters that his ministry will tighten regulations on amusement park operators and require them to check equipment regularly.
Expoland, Suita, Osaka Prefecture, was crowded with holidaymakers when the accident occurred at around 12:50 p.m. Saturday.
The second car of the roller coaster derailed and hit a 1.1-meter-high guardrail running alongside the track.
Osaka police have launched an investigation into the accident on suspicion of professional negligence resulting in death and injury.
Metal fatigue is suspected of causing the axle break, the sources said.
