A deadly fire tore through a Swiss nightclub during New Year’s Eve celebrations in Crans-Montana, killing 47 people and injuring around 100, according to officials. The blaze broke out at about 1.30am local time (12.30am GMT) in the basement of Le Constellation, a popular venue in the centre of the Alpine resort town.

Video from inside shows flames racing across the low ceiling of a crowded bar while music continues, before panic sets in and people surge toward what witnesses said was a single, narrow staircase exit. Several survivors described scenes of people suffering severe burns and others collapsing from smoke, with some trying to smash windows to let in air.

Police have not confirmed the cause, but multiple witnesses said the fire began when a sparkler or candle—held aloft during a champagne presentation—came too close to the wooden ceiling. Promotional footage of the club shows staff circulating with champagne bottles fitted with sparklers. Photos of the interior also appear to show ceiling soundproofing foam, which witnesses feared may have helped the fire spread.

Authorities said the incident involved a flashover, triggering one or more explosions. Emergency crews mobilised dozens of ambulances and multiple helicopters, with hospitals reporting heavy strain from burn victims. Swiss prosecutors said terrorism has been ruled out, and warned against speculation as investigators work to identify victims, including foreign nationals reported missing.