On Friday, Swiss authorities began the grim process of identifying the mostly young victims of a fire that killed around 40 people and injured more than 100 at a ski resort in Crans-Montana.

Italian authorities, citing information from Swiss officials, said the death toll could climb as high as 47. Several Italian nationals were reportedly among those killed, injured, or still missing.

The fire ripped through the Le Constellation bar in the Alpine resort town in the early hours of Thursday, turning a packed night of celebration into panic and tragedy. Officials noted the blaze appeared to be an accident rather than an attack.

Swiss authorities stated that the severity of burns suffered by many victims could delay formal identifications for days, as forensic teams worked to determine the identities of those killed.

Police and government officials said a large proportion of the victims were teenagers and young adults, with many believed to be between 16 and 26 years old. In Switzerland, the legal drinking age for beer and wine is 16.

“All this work must be done because the information is so devastating and sensitive that nothing can be communicated to families unless we are absolutely certain,” said Mathias Reynard, head of government for the canton of Valais. He added that investigators were using dental records and DNA samples to identify the victims.

Italy and France reported that some of their nationals remain missing, and Antonio Tajani visited Crans-Montana on Friday to lay flowers. 

The number of Italians involved in the incident currently stands at 19, according to the , which cited Italy’s foreign ministry.

Australia has also confirmed that one of its nationals was injured. 

Some survivor accounts and social media videos suggested the bar’s basement ceiling may have caught fire when sparking candles used during bottle service came too close, though authorities said the cause had not yet been formally determined.

Officials said the fire triggered the violent ignition of combustible gases—an event known to English-speaking firefighters as a flashover or backdraft, according to The Associated Press.

Axel Clavier, a 16-year-old survivor of the blaze, described “total chaos” inside the bar. One of his friends died, and “two or three were missing,” he told the outlet.

Clavier said he did not see the fire start but recalled waitresses entering the room carrying Champagne bottles topped with sparklers shortly before the blaze broke out.

Another witness told BFMTV that people smashed windows to escape the flames. Panicked parents rushed to the scene to check if their children were trapped inside.

Helicopters and ambulances rushed to the scene to aid victims from multiple countries, officials said. , with intensive care units and operating theaters reaching capacity.

Swiss authorities later noted that the burn unit in Valais was full, and Italy made a major burns unit in Milan available to treat the injured. 

By Friday, mourners had started leaving flowers and candles at a as the resort town grappled with the scale of the tragedy.

‘ Bradford Betz, Greg Norman, Emma Bussey, as well as The Associated Press and Reuters contributed to this report.