The Kobe District Public Prosecutors Office on Wednesday indicted Mr. Masao Yamazaki, president of West Japan Railway Co., on a charge of professional negligence leading to death and injury in connection with the April 2005 train crash that killed 106 passengers plus the driver and injured 562 passengers. The indictment, a rare move on the part of public prosecutors, concludes a criminal investigation that lasted slightly more than four years.

In past train accidents, public prosecutors were cautious about indicting high-ranking officials of train companies and their targets were mainly drivers and conductors. Their decision this time to indict a train company president indicates a change in attitude on their part. It should compel train company executives to take a more serious approach to train safety.

But one wonders whether Mr. Yamazaki is the sole person criminally responsible for the accident — the worst rail accident since the privatization and division of Japanese National Railways in April 1987. Bereaved family members of accident victims had filed complaints against three former JR West executives and eight former JR West officials in charge of safety measures and train operations, but the public prosecutors did not indict them. It is hoped that the trial will disclose their roles in connection with the accident.

On the morning of April 25, 2005, a seven-car "rapid service" (express) commuter train, bound for Doshisha-mae Station from Takarazuka Station, dashed into a right curve in front of Amagasaki Station on the Fukuchiyama Line in Hyogo Prefecture at a speed of 116 kph. The speed limit was 70 kph. The 23-year-old driver applied the brake a few times, but the first five cars derailed and the train slammed into a nine-story condominium building by the tracks. No Automatic Train Stop system (ATS) was installed at the scene.

The curve used to be a 600-meter-radius curve, but JR West had replaced it with a 304-meter-radius curve on Dec. 20, 1996, so that the Fukuchiyama Line would connect with the Tozai Line, which was scheduled to be open in March 1997. Along with the opening of the Tozai Line, the train schedule was changed and the number of "rapid service" trains runs was increased.

The public prosecutors said the replacement of the old curve was unprecedented in that the radius was halved, making the new curve very sharp. They also pointed out that the increase in the number of "rapid service" trains whose speed could reach 120 kph shortly before entering the curve increased the danger for such trains. They said that around the time the accident occurred, the curve was the most dangerous curve among JR West's train operating districts.

The public prosecutors alleged that although Mr. Yamazaki, who was a managing director entirely entrusted with the task of managing safety measures, was aware of the danger, he failed to install ATS, thus leading to the accident. They referred to a Dec. 4, 1996, accident on the Hakodate Line of JR Hokkaido Co., in which a cargo train derailed in a 300-meter-radius curve and pointed out that Mr. Yamazaki was told in a JR West meeting that the accident could have been averted if ATS had been installed. He therefore should have been aware of the danger inherent in the curve near Amagasaki Station, they said.

Mr. Yamazaki, who resigned as president after he was indicted, has insisted that he could not foresee the accident because he never expected a train to enter the curve at a speed so much higher than the limit.

The prosecution may face difficulty in making its case because, at the time of the accident, the government had not imposed a legal requirement to install ATS and there were many similar sharp curves in many parts of the nation not equipped with ATS. Also, JR West had experienced no operational problems for slightly more than eight years after the new, sharp curve was installed on the Fukuchiyama Line.

Probably the biggest factor contributing to the accident was JR West's corporate culture and labor management. The driver was apparently worried about being punished for overrunning a stop at Itami Station shortly before the accident. In the past, he had received punitive education three times for errors and had had his wages and bonuses docked. There is evidence suggesting that the driver was paying close attention to radio communication in which the conductor reported the Itami Station delay to the operations center and was thus distracted from concentrating on safe driving.

It is important to make clear Mr. Yamazaki's criminal responsibility in the trial. But what is more important is to shed light on why and how the accident occurred, including the working conditions and pressure that JR West train drivers faced, and what went wrong with JR West as an organization.