The Sierre coach crash occurred on 13 March 2012 near Sierre, Switzerland, when a coach carrying school teachers and pupils crashed into a wall in the Sierre Tunnel. Of the 52 people on board, 28 were killed in the crash, including both drivers, all four teachers, and 22 of the 46 children. The other 24 pupils, all aged between 10 and 12, were injured, including three who were hospitalised with severe brain and chest injuries.
The coach was one of three operated by the Aarschot-based Top Tours company and was transporting mostly Belgian school teachers and students from a skiing holiday in Val d'Anniviers back to their two schools in Belgium. It crashed at around 9.15 pm CET while travelling on the A9 motorway near Sierre, in the southern canton of Valais.
It was Switzerland's second-worst road accident in history and the country's worst in a motorway tunnel. The investigation into the crash initially closed inconclusively in May 2013, having ruled out a number of factors that had been the subject of media speculation but failing to identify a cause. A further public investigation, closing at the end of June 2014, attributed the crash to a non-criminal error on the part of the coach driver. Media speculation has continued.