Police examine the site of a roller coaster accident in Osaka on May 5. KYODO PHOTO

The broken ends of the axle that failed in the accident were almost flat, which metallurgical experts say is typical of a metal fatigue fracture, the sources said.

Officials at Expoland park in Suita said the axle had been in use since the roller coaster debuted in March 1992, and the firm was not aware of the part's life span.

Yoshino Kogawara, a 19-year-old company employee from Higashi Omi, Shiga Prefecture, was killed in the accident. Her friend, Sayuri Furukawa, 20, from the town of Toyosato, also in Shiga Prefecture, was seriously injured. Eighteen other people sustained slight injuries.

The Japan Times Weekly: May 12, 2007
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