Students of a Christian Youth Group from Lommel and Heverlee in Flanders.
Belgium had experienced a wonderful ski holiday in the Swiss Alps.It was a class trip many of them had been looking forward to for some time.
Singing and full of good memories class mates boarded a bus back to Belgium on Tuesday night.
The trip home ended in a tragic death for 28 out of 52 passengers, including the two driver and 22 children
The deadly accident happened after leaving Sierre in the Swiss canton of Valais (Wallis), the Swiss news agency SDA-ATS reports.
The buss crashed against a tunnel wall.
Another 24 children were reported injured.
The children were travelling from Vald'Anniviers and were returning to Belgium.
The bus was travelling towards Sion last night local time and hit a wall in the motorway tunnel running from east to west and exiting at Sierre.
The Valais police commander told a press conference the tragedy was "unprecedented' and that even seasoned rescuers had been traumatised.
Helicopters and ambulances ferried the injured to four hospitals, police said.
In Brussels, the Belgian foreign ministry said most of the children were aged around 12 and the bus was one of three hired by a Christian group.
Surgeon Jean-Pierre Deslarzes said at one of the hospitals: "All the rescuers were shocked by what they have experienced."
"This tragedy will hit the whole of Belgium," the Belgian ambassador to Switzerland Jan Luykx told the Swiss news agency SDA-ATS. "The magnitude of the accident is difficult to digest." The Belgium ambassador was on the scene and was shaken at a press conference Wednesday morning.
Source: wire input