Candles burn near a giant photo as people pay tribute to late French Olympic swimmer Camille Muffat in Nice, March 10, 2015. Three French sports stars - Olympic swimmer Camille Muffat, yachtswoman Florence Arthaud and boxer Alexis Vastine - were among 10 people killed when two helicopters collided in Argentina on Monday during the filming of a reality TV show. Authorities said it was still unclear what caused the accident in the rugged western province of La Rioja, near the Andes Mountains. REUTERS/Jean-Pierre Amet (FRANCE - Tags: OBITUARY SPORT DISASTER TPX IMAGES OF THE DAY)