The fire in the Le Constellation bar in central Crans-Montana took a violent turn during New Year's celebrations.
Around 40 people have so far been confirmed dead in the fire, according to Swiss police.
In addition, 115 people were injured, many of them seriously. According to the public service company SRF, at least 30 injured people have been flown by air ambulance to hospitals in Lausanne, Geneva and Zurich, among others. Some have reportedly been taken to a children's hospital and at least one person has also been flown to Stuttgart in Germany. A spokesperson for a hospital in Geneva told the BBC that the youngest person being treated for severe burn injuries is 15 years old.
Swiss President Guy Parmelin called the incident "one of the worst tragedies ever in our country" and declared five days of national mourning.
The work of identifying the dead is ongoing, but is said to take days or even weeks. People of several different nationalities are affected. France and Italy have confirmed injured and missing citizens. The Swedish Ministry of Foreign Affairs has announced that the embassy in Bern is in continuous contact with local authorities and is trying to obtain more information about the incident. There is no information about Swedes affected.
The fire was reported at 1:30 a.m. It is still unclear exactly how the fire started, but it is not being investigated as a deliberate attack.
Witnesses described an explosive fire, saying the ceiling caught fire when people waved champagne bottles with small fireworks. SRF reports that the fire quickly spread from the ceiling to "all flammable surfaces" in the venue.
The bar Le Constellation is described as a popular spot among young people. The venue has two floors, with a staircase leading down from the upper floor to a basement room, reported local newspaper Le Nouvelliste. According to several media outlets, the fire broke out in the basement, causing panic as people tried to get out.
