Swiss authorities believe sparkles on Champagne bottles started a fire that killed 40 New Year revelers at a packed bar in the Ski resort of Crans-Montana.

Dozens of people badly burnt in the fire early Thursday in the glitzy Alpine town were taken to nearby countries for urgent treatment, while authorities pointed the finger at lit sparklers attached to champagne bottles igniting foam on the ceiling.

People continued to bring flowers, candles and messages on Saturday to a makeshift memorial near the scene of the tragedy at Le Constellation bar, where people have often simply stood in stunned silence.

"Courage to all the victims' families, we're thinking of Stefan and hoping he's okay; a hero," said one message. Cards read: "We're thinking of you" and "May they rest in peace."

The tragedy remains the topic of every conversation, filled with pain, sadness, and also incomprehension.