The report presented by the public prosecutor of canton Valais where the accident occurred, ruled out the involvement of a third party, shortcomings in the road surface or the tunnel infrastructure, excessive speed, alcohol or technical problems with the coach.
Investigations are now concentrating on the driver. It is hoped to have the results of toxicology tests on the driver before the end of summer although it is already known that he had not drunk any alcohol.
The 34-year-old driver had taken over the wheel from his colleague shortly before the crash occurred. The twin-running 2.6km Sierre tunnel, which features two lanes in each direction and emergency laybys at 600m intervals, has a maximum speed permitted of 100km per hour, and the coach was travelling at between 99 and 101km per hour.
The coach touched the right curb about 75m before site of the collision, travelled along it and crashed into a wall head on within less than three seconds. There were no significant indications that the driver had tried to change direction or brake.
The crash on March 13 left a total of 28 people dead – 22 of them children returning to Belgium and Holland from a school skiing trip. 24 passengers received treatment in hospital for injuries.
