Fire at Swiss Ski Resort Kills Roughly 40

Popular with teens, Le Constellation is close to the base of the town’s ski runs and offers a ground-floor lounge with a speakeasy-style bar in the basement.

Within minutes, a fire had consumed the establishment. Videos posted on social media showed flames creeping along the ceiling and billowing out of ground-floor windows, with people screaming as firefighters and other first responders attempted to control the blaze.

“The first police arrived in a scene of chaos, a scene of drama,” said Stéphane Ganzer, head of security for Valais, the Swiss canton where the fire took place. 

Through the night, ambulances drove victims to hospitals down in the valley.

By Thursday morning, a white tent had been erected over the scene as officials attempted to identify victims, many of whom they expected to hail from multiple countries. The process is expected to take several days.

Swiss President Guy Parmelin, who took office Thursday, visited Crans-Montana. At a press conference, he called the fire “one of the worst tragedies Switzerland has known.”

Crans-Montana is a French-speaking Alpine resort set on a sunny shoulder of the Rhone valley. Popular with international tourists, it attracts an affluent crowd who come for skiing, its famous golf course and luxury shopping in the cobbled town center.

On New Year’s Eve, locals and visiting tourists had poured into the town to party after firework shows lighted up the mountainside at the stroke of midnight.

The fire doesn’t appear to have been an act of terrorism, but the exact cause hasn’t yet been determined, said Beatrice Pilloud, attorney general for Valais.

Officials said the fire spread quickly but there was no sign of an explosive device. Reports of an explosion may have stemmed from a flashover, when a fire spreads quickly and can sound like an explosion, officials said.

Swiss and French press reports cited witnesses who said that sparkler candles used by staff when serving drinks in an underground portion of the bar may have inadvertently started the blaze. They also described a crush of people who attempted to flee from a single staircase.

Photos posted to the social-media accounts of Le Constellation—which have since been made private—depicted staff using sparkler candles, including while serving drinks.

The bar, which listed itself on a local website with a capacity of 300 people, also advertised late-night DJ sets and dancing on its social-media feed.

Officials, who spoke at both morning and evening news conferences on Thursday, declined to comment on the possible use of pyrotechnics in the bar, but said the bar’s exits and its compliance with safety norms were under scrutiny.

“I saw the staircase. I went and verified it on-site myself,” said Pilloud, the attorney general.

Hundreds of fire and rescue forces were dispatched to the scene and a no-fly zone was imposed over the Swiss Alps resort, according to police.

The canton’s hospital system was overwhelmed with victims of the fire, officials said, leading to patients with serious injuries being transferred by helicopter to other parts of the country. Some 20 serious burn victims were being treated at a specialized center in Lausanne, officials said.

Authorities asked people to avoid skiing because injuries could overload local hospitals already at capacity.

On Thursday morning, the smell of smoke still hung in the town’s air. Crowds clustered by police barricades alongside television crews, while people wandered the streets in a daze.

Police manned a roadblock next to a sign, placed in the prior days because of a lack of precipitation, that warned of the risk of fire. “Fires and fireworks prohibited,” it read.

Peter Saidel contributed to this article.

Write to Angus Berwick at angus.berwick@wsj.com and Sam Schechner at Sam.Schechner@wsj.com