Swiss prosecutors have launched a criminal investigation against the two managers of a bar where a deadly fire killed at least 40 people on New Year’s Day. The blaze broke out around 1:30 a.m. at Le Constellation bar in the ski resort of Crans-Montana, during a packed party mostly attended by young people. Investigators believe fountain sparklers fixed on champagne bottles, held too close to the ceiling, started the fire. The ceiling, reportedly covered with foam soundproofing panels, caught fire quickly. Authorities suspect the sparkler use, fire safety measures, and soundproofing materials may violate rules. The prosecutors said the suspects may face charges for homicide by negligence, bodily harm by negligence, and arson by negligence. Police said many victims are teens and young adults. Officials are still identifying the dead and injured as families await news. Senior regional prosecutor warns that "possible prosecutions" will follow if criminal fault is proven. Stéphane Ganzer, Valais’ top security official, told SRF radio, "Something didn't work and someone made a mistake, I am sure of that." However, Nicolas Féraud, head of Crans-Montana municipality, told RTS radio that he believed safety checks on the bar had not been weak. Authorities will also examine fire extinguishers, escape routes, and permissions for the sparklers used.