A coach full of Belgian and Dutch school children, parents, drivers and teachers – 52 people in total – were returning from a skiing trip in Val d’Anniviers when their vehicle collided at high speed with a wall in a motorway tunnel.
The accident happened in Valais (also known as Wallais) and is believed to be the worst road accident in Swiss history.
As well as those tragically killed in the accident, the remaining 24 were injured, with several requiring helicopter rescue to take them to Swiss hospitals.
The 11 and 12 year old children were from the Flemish towns of Heverlee and Lommel near Brussels.
Early reports have suggested that the coach veered off the road, hit a kerb then collided with the concrete wall. The speed limit in the tunnel is 100 km/h (62 mph).
The crash occurred at just after 9pm on Tuesday night. The coach was one of three in a group returning the children home.
Belgian Prime Minister Elio Di Rupo said “A very sad day for all of Belgium. Words are not enough for this terrible accident.”