The mangled front of the bus. The crash happened in a tunnel in Sierre, in the Swiss canton of Valais. Sebastien Feval /AFP/Getty Images hide caption itoggle caption Sebastien Feval /AFP/Getty Images The Two-Way 'Tragic Day For All Of Belgium': 22 Children Killed In Bus Crash March 14, 2012 They were heading home from a Swiss ski vacation when the bus they were on hit a tunnel wall head-first. Six adults also died. Twenty four children were injured.