Swiss investigators link deadly ski resort fire to sparkling flares on Champagne bottles igniting the crowded bar's ceiling.

The fire broke out at 1.30 a.m. (0030 GMT) in a bar called "Le Constellation", police said in a statement.

A 'fire of undetermined origin' broke out in a bar in the luxury Swiss ski resort town of Crans Montana, police said in a statement, adding that 'a major emergency response is…