Three star French athletes, including two Olympic medalists, were among the 10 people killed in a helicopter crash in Argentina. Five other French victims were the crew for a reality TV show and both Argentine pilots died.

The athletes were swimmer Camille Muffat, 25; yachtswoman Florence Arthaud, 57; and boxer Alexis Vastine, 28, reports The Guardian. Muffat won three medals during the 2012 London Olympics, while Vastine won a bronze at the 2008 Beijing games.

The crash occurred in the La Rioja province near the Andes mountains. The two helicopters collided just after taking off and there were no survivors.

“The sudden death of our fellow French nationals is a cause of immense sadness,” French President Francois Hollande said in a statement, reports BBC News.

Muffat, Arthaud and Vastine were taking part in a reality series called Dropped, which airs on TF1. In the series, the athletes are blindfolded and dropped in the wilderness to test their survival skills.

The French sports community is mourning the loss of three stars, who were all well known in France. “The whole of French sport is in mourning because we have lost three huge champions,” sports minister Thierry Brillard told RTL radio.

“We learn with great sadness about the accident during the filming of the Dropped show,” TF1 said in a statement. “All TF1 teams come together in this terrible time with the pain of the families and relatives of the victims.”

TF1 said that the show will be postponed, with remaining crew heading back to France.

This is actually the second time a TF1 reality show has been involved in a tragedy. In 2013, a 25-year-old contestant died during the filming of Koh-Lanta. The doctor that worked for the show later committed suicide after media criticism.

screenshot of Camille Muffat from BFMTV YouTube video