Initial investigations suggest the fire that tore through a Swiss ski resort bar New Year’s Eve started when “fountain candles” attached to Champagne bottles were carried aloft too close to the ceiling, the local prosecutor said on Friday.

“Everything suggests that the fire started from the burning candles, or ‘Bengal lights,’ that had been attached to Champagne bottles. These went too close to the ceiling. From there, a rapid, very rapid and widespread conflagration ensued,” prosecutor Beatrice Pilloud told a news conference.

The latest news came as investigators continued the painful task of identifying the at least 40 people killed at the party at Le Constellation bar in the upscale Swiss ski resort of Crans-Montana.