Coach crash investigators have revealed the latest findings from their inquiries.
In a joint news conference headed by the Belgium Prime Minister and the President of the Swiss Federal Council, details emerged of what Elio Di Rupo called a tragic, dark day for both countries.
It appears the vehicle was not breaking the speed limit and that most of the passengers were wearing safety belts, but the impact of the crash may have rendered them useless.
Chief investigator, Olivier Elsig, said they are now working on three main theories. The first is that there may have been some sort of technical problem with the coach, although it was fairly new and recently serviced.
Secondly, the crash may have been because the driver suffered some sort of malaise. This will be determined by the results of an autopsy. Thirdly, and this is their least favoured theory he said, the crash may be the result of human error.