Ten French sports stars participating in a reality TV show, Dropped, were killed on Monday when their helicopters collided mid-air during filming in northwestern Argentina. Among those that died were three Olympic champions – Gold medalist swimmer Camille Muffat, Olympic boxer Alexis Vastine and champion sailor Florence Arthaud.

The weather conditions were good and cause of the crash remains a mystery with suspicions that the two helicopters may have crashed. The Argentine media showed the wreckage in flames on the dry scrubland.

The crash occured near Villa Castelli about 1,170 km away from Buenos Aires.

Dropped is a popular celebrity show on channel TF1 that flies celebrities to rough terrains by helicopters and films their attempts to find food and shelter. TF1 issued a statement: “We learn with great sadness about the accident during the filming of the show, Dropped. All TF1 teams come together in this terrible time with the pain of the families and relatives of the victims.”

The show has been postponed and the rest of the crew is returning back to France.