Three French sports personalities participating in a reality TV show were among 10 people killed on Monday (Mar. 9, 2015) when their helicopters collided in mid-air while filming in northwestern Argentina.

Champion sailor Florence Arthaud, Olympic gold medallist swimmer Camille Muffat, Olympic boxer Alexis Vastine and seven others died when two helicopters filming the survival series “Dropped” smashed into each other in the rugged mountains of La Rioja province, local officials said.

“Apparently, the two helicopters collided as they were filming. There are no survivors,” provincial spokesman Horacio Alarcon told AFP.

He said the weather conditions were good and the cause of the crash, which happened late afternoon local time on Monday, was unknown.

Local media showed the wreckage of the two helicopters in flames on the dry scrubland in the northwestern Argentinian province.

Eight French passengers and their two Argentine pilots died in the crash, a police source said.

Arthaud, 57, was best known for her victory in the 1990 Route du Rhum, a prestigious transatlantic singlehanded race, held every 4 years in November, between Saint Malo, Brittany, France and Pointe-à-Pitre, Guadeloupe. She was sailing the VPLP-designed 60-foot trimaran Groupe Pierre 1er.

In 1997, she joined skipper Bruno Peyron (FRA) onboard the 86-foot catamaran Explorer in the Transpac Race, setting the fully crewed multihull elapsed time record of 5 days, 9 hours, 18 minutes, 26 seconds.

The current Transpac record, set in 2005 by Olivier de Kersauson (FRA) on the 90-foot trimaran Geronimo, is 4 days, 19 hours, 31 minutes, 37 seconds.

President Francois Hollande led the tributes, saying the “brutal death of our compatriots is an immense sadness.”

“The whole of France is in mourning this morning,” said Prime Minister Manuel Valls.

The reality TV show, called “Dropped”, involved eight sports stars being dropped into inhospitable environments for an adventure- and survival-themed show.