An American teenager is among three people who have been killed in an avalanche near the Zermatt resort in the Swiss Alps, police have said. The 15-year-old was killed alongside a man and woman whose identities have not yet been confirmed, police said. A 20-year-old Swiss man was flown to hospital with serious injuries after the avalanche at 2pm local time (1pm UK time) on Monday. It took place in an off-piste area of the Riffelberg slopes, which sit above the Zermatt resort and below the famed Matterhorn mountain. Read more from Sky News: Gang war turns 'peaceful' country into...