The Federal Court has ruled that criminal charges cannot be brought against a coach driver who died along with 22 children and five other adults in 2012. The court also rejected the appeal of two sets of parents.
The coach was carrying 52 passengers from two Belgian schools when it slammed into a tunnel wall on the A9 motorway between Sierre and Sion in western Switzerland. Twenty-four more children were injured.
Although the exact cause of the crash – one of the worst in Switzerland – remains unknown, investigators confirmed initial suspicions of driver error. They said the 34-year-old driver had an unusual heart condition that may have brought on sudden illness, but this theory is impossible to prove conclusively.
The driver was also taking anti-depressants, but these are thought unlikely to have contributed to the accident. The cantonal public prosecutor also ruled out the possibility of the crash being linked to suicidal impulses.
An autopsy revealed that the driver had not been drinking and crash scene investigators found the bus had been travelling within the speed limit.
Previous investigations had found the bus to be in good mechanical condition and that there were no shortcomings with the road surface or tunnel infrastructure.
The cantonal prosecutor therefore ended criminal proceedings.
The parents of two children who died appealed to the Federal Court in Lausanne for the criminal proceedings to be continued, arguing that the cause of the accident should be fully clarified.
On Friday the court disagreed, ruling that it was not possible to bring charges against the dead driver.
It said the aim of criminal proceedings was limited to determining offenders and carrying out justice. Mere circumstantial evidence of a potential cause of an accident was not enough to pursue criminal proceedings, it explained.
The parents still have the option of seeking compensation through a costly civil lawsuit.
swissinfo.ch and agencies