Swiss authorities have said they believe a fire at a ski resort bar was "caused by sparklers attached to champagne bottles that came too close to the ceiling". BBC Verify have verified previous video posted in 2024 showing people carrying lit sparklers attached to champagne bottles inside Le Constellation nightclub, Switzerland. At least 40 people were killed in the fire in the early hours of New Year’s Day. Tap the link in BBCNews's bio for our latest reporting on the fire. #Switzerland #BBCVerify #BBCNews