The prevalence of sparklers at a Swiss ski resort bar where dozens of people died in a fire this week has been branded "irresponsible", as authorities probe potential compliance issues there.
At least 40 people were killed and 119 injured when Le Constellation bar, in the alpine town of Crans-Montana, burst into flames around 1:30am, local time, on January 1.
A multi-agency investigation is examining whether revellers were crushed trying to flee the burning building via a narrow staircase, whether the emergency exit was blocked, whether foam cladding on the ceiling was legal, and if too many people were inside the venue at the time the fire broke out.
Authorities on Friday revealed they believed so-called fountain sparklers were responsible for starting the blaze.
"Even if they're small, using them in such a venue seems pretty irresponsible to me," said Italian Foreign Minister Antonio Tajani, who travelled to the town after the fire because dozens of his country's citizens are injured or missing.
The sparklers, sometimes known as bangers, are readily available across Europe and elsewhere, but not in Australia.
Beatrice Pilloud, the local region's attorney-general, said investigators had already reviewed videos filmed in the venue shortly before the blaze began.
The clips show wild New Year's Eve celebrations, including people sitting on each other's shoulders and waving champagne bottles with fountain sparklers attached to them close to the ceiling.
"From that, the blaze began very quickly," Ms Pilloud said, adding the two bar's two French owners had already been interviewed.
"The next steps of the investigation will focus on the [building] work carried out within the bar, the materials used, the operating permits, the safety measures ... the number of people who were present that evening and the number of people the bar is authorised to hold."
Ms Pilloud said compliance issues relating to the foam cladding attached to the bar's roof were being scrutinised and that criminal charges were possible, pending the investigation's findings.
Swiss authorities have already said the bar was engulfed after a "flashover", which occurs when all combustible materials in an enclosed room ignite at the same time.
They've also described most of the casualties as being young, and that many have not yet been identified.
At least one Australian was injured in the fire.
"I remind you that these young people were not in a nightclub, but a bar that is not subject to the same rules and safety conditions," said Thierry Fontaine, the president of a hospitality union in neighbouring France told media outlet BFMTV.
"In a bar, you're not supposed to dance or party or have this kind of action."
[Map]Swiss liquor licensing laws are more relaxed than what Australians might be used to.
In most regions, including the one Crans-Montana is in, 16-year-olds can buy and consume beer and wine.
Children under the age of 16 are legally permitted to be inside bars like Le Constellation after 10pm, as long as they're accompanied by adult guardians.
Before that, they can enter unaccompanied, although venues may enforce their own, stricter policies.
Greek authorities have said a 15-year-old girl, who'd planned to celebrate the new year at Le Constellation, is missing.
Steve Hajdu, who is living in an apartment above Le Constellation bar with his family for the ski season, told the ABC he rushed outside to help when the fire broke out and described the scene as "a huge mess".
"We know four people that are missing," he said. "We're thinking about them. We're praying for them. It's something that's very hard for us to swallow."
Mr Hajdu, a father-of-three, said his family no longer wanted to live in the building, which now felt like it was "on top of the cemetery".
Authorities say they're working as fast as they can to identify the casualties, although many friends and relatives are still searching for answers.
More than half the people injured, officials said on Friday, are Swiss.
Laetitia Brodard, from Lutry, near Lusanne, is looking for her 16-year-old son Arthur.
"I'm living a nightmare, a nightmare. Either I find my son in the morgue, or I find him in critical condition. It's terrible," she told the Le Temps newspaper.
Among the first casualties to be identified is a youth player for French football club FC Metz, Tahirys Dos Santos.
The 19-year-old's manager, Christophe Hutteau, told BFMTV the athlete was in "terrible pain" and had burns to "30 per cent of his body".
Le Constellation bar is owned by French restaurateurs Jacques and Jessica Moretti.
"We can neither sleep nor eat, we are all in very bad shape," Mr Moretti told the newspaper 20 Minuten, adding they intended to cooperate with authorities.
Crans-Montana's world-renowned snow, luxury shopping and high-end restaurants attract scores of wealthy foreign tourists during the winter months.
A local woman, who didn't want to be identified, criticised holiday makers who'd already returned to the slopes.
Her cousin works at a local hospital, which has been inundated with burns victims after the blaze.
"They don't have enough room for people who injure themselves on the mountain," she told the ABC.
"They shouldn't be there."
Many of the victims have been transferred to hospitals in other locations around Switzerland, while some have been taken to health facilities in nearby countries.