Twelve people have been killed when their bus plunged into a ravine in south-western Switzerland.
It is not clear what caused the bus to come off the road
Fifteen others were injured, four seriously. Most of those only survived because they were thrown from the bus before it rolled down the ravine.
Dozens of rescuers descended into the ravine using ropes to get to the wreckage 250m (800 feet) below.
The accident happened on the Great-St-Bernard pass in the region of Valais, close to the Italian border.
The bus had gone out of control, slamming through a crash barrier and rolling several times down a sleep slope, finally stopping in a stream.
More than 150 rescuers were sent to the scene. They rescued one person from the wreckage, but the others were dead - among them a 15-year-old boy.
A helicopter was used to take survivors to hospital.
The accident happened shortly before 1000 (0800 GMT), between the Swiss towns of Orsieres and Liddes. The bus, carrying 24 passengers, two drivers and an attendant, had left the capital, Bern, early on Sunday, on its way to north-west Italy.
It had been snowing overnight, but when rescuers arrived the road was only wet, said police spokesman Renato Kalbermatten.
The Great-St-Bernard pass is one of the main routes through the western Alps near the borders of France and Italy.