( CNN ) Three French sports stars were among 10 people killed when two helicopters collided in Argentina on Monday evening , authorities said . The helicopters were reported to be heading to a gorge in northwestern Argentina for the filming of the reality TV show `` Dropped '' for the French broadcaster TF1 . Eight French passengers and the choppers ' two Argentinian pilots died in the midair crash near the town of Villa Castelli in La Rioja province , Argentina 's state news agency Telam reported , citing local authorities . The dead included the famed sailor Florence Arthaud , who in 1990 broke the record for crossing the North Atlantic alone ; the swimmer Camille Muffat , who won three medals at the 2012 Olympics in London ; and the boxer Alexis Vastine , who won a bronze medal at the 2008 Olympics in Beijing . Members of the TV production team were among the other French victims , French authorities said . Former French soccer star Sylvain Wiltord , a contestant on the show who was n't involved in the crash , expressed his shock . `` I 'm sad for my friends , '' he tweeted . `` I 'm shaking , I 'm horrified , I 'm lost for words . '' Muffat 's boyfriend , William Forgues , told CNN 's French affiliate BFMTV of his shock at hearing the news of the 25-year-old swimmer 's death . Clearly emotional , he said her agent had called him soon after midnight , herself in tears , to tell him of the crash . Muffat , he said , was known as `` madame 100 % '' because she succeeded in so many things . He said she was happy and satisfied to be taking part in the show . `` To be over there was her choice , 100 % , '' he said . At the 2012 London Olympics , Muffat won the gold medal in the 400-meter freestyle , silver in the 200-meter freestyle and bronze in the 4×200-meter freestyle relay . French President Francois Hollande expressed his condolences to the families of the victims in a statement . The sports stars `` made France shine so brightly '' during their careers , the statement said . The crash happened within moments of takeoff in good weather conditions , Telam reported , citing witnesses who spoke to a local radio station . The helicopters , which belonged to local governments in the region , collided about 100 meters ( 328 feet ) above the ground , the news agency said . Police and investigators were at the scene of the crash . A manslaughter investigation has been opened in France into the incident , to be led by the Air Transport Gendarmerie , a representative for the Paris prosecutor 's office said Tuesday . It is standard procedure to launch an investigation if French nationals die abroad . Five national police officers were en route from Paris to Argentina on Thursday , authorities said . Their mission there is to collaborate with the Argentinians and assist in the identification of victims . The TV show involved sports stars being helicoptered into remote areas while blindfolded and then having to survive in the wilderness , according to French media . `` We learn with immense sadness of the accident that occurred during the filming of the show 'Dropped , ' `` TF1 said in a brief statement . TF1 's staff `` come together in this terrible time with the pain of the families and those close to the victims , '' it said . CNN 's Nelson Quinones , Laura Akhoun and Marilia Brocchetto contributed to this report .
Paris prosecutor 's office opens a manslaughter investigation into the crash . The dead include French athletes Alexis Vastine , Camille Muffat and Florence Arthaud . The helicopters were on their way to a gorge for the filming of a reality TV show .