A tour coach has overturned on a mountain road in the eastern Swiss canton of Graubünden, leaving several people dead and a number of others injured, authorities have confirmed.The crash took place on Thursday on the stretch of road linking the villages of Susch and Zernez, deep in the Engadine valley.Local police confirmed the fatalities via a post on X, though they have not yet released the number of victims, their nationalities, or any explanation for what caused the vehicle to leave the road.The Dutch Federation of Travel Agencies (ANVR) told AFP that the coach belonged to the tour company Oad and was carrying 48 passengers, all of them from the Netherlands.Television footage from Swiss broadcasters showed emergency crews swarming the scene, working around the coach as it lay overturned on an embankment beside the carriageway. Helicopters were seen landing nearby to assist with the response.A police spokesman told AFP that the force did not wish to provide a more detailed toll until the victims’ families had been informed.According to the ANVR, the coach left the Netherlands on Monday and was on a day trip to Switzerland from Austria when the crash happened.Zernez sits at the gateway to the Swiss National Park, a rugged Alpine reserve covering more than 100 square kilometres across the Engadine region, and is a popular starting point for visitors exploring the region.Police say the investigation into the cause of the crash is ongoing.