According to available information, a woman was holding a bottle of champagne with a firework attached while she was on the shoulders of other patrons. A spark from the firework ignited a fire that quickly escalated into what is known as a flashover — the moment when all combustible materials ignite simultaneously, leading to a series of explosions, Swiss authorities claim.
In the previous year, a promotional video for the club showed staff carrying bottles of champagne with lit sparklers through a crowded hall.
According to information provided by the French publication 24Heures, one witness described the panic and crush among patrons trying to reach the only exit via a narrow staircase leading from the basement.
An eyewitness, commenting on the situation, told the BFMTV channel: "The explosion happened because of the fireworks hidden in the champagne bottle. The flames engulfed the entire ceiling of the bar."
The fire spread rapidly throughout the venue, and soon it became impossible to breathe. Among the victims, rescuers reported many foreign tourists, and there may also be teenagers among the injured.
It was also reported that the basement bar had only one exit, which had previously raised concerns among some patrons.
