Tributes have been paid to "immense" former France rugby union international Christophe Dominici, who has died aged 48.
Dominici was best known for helping France knock New Zealand out of the 1999 Rugby World Cup.
A witness saw him climb the roof of a disused building at Saint-Cloud park, near Paris, on Tuesday before falling, officials say.
Prosecutors have opened an inquiry into the cause of his death.
"So much sadness. Christophe Dominici was an immense player, an artist. His sudden death is a shock," said sports minister Roxana Maracineanu.
Dominici played 67 times for his country and won the French championship five times with Stade Français before retiring in 2008. In recent years he had worked as a pundit for French radio and TV.
His 1999 World Cup semi-final performance spurred France to a sensational comeback, as he darted down the left of the pitch and seized the ball ahead of two New Zealand defenders to score a try. The All Blacks were leading the game at the time and had the brilliant Jonah Lomu in their line-up.
Known as Domi, he was 1.72m (5ft 6in) tall and earned a reputation for weaving runs that could change the course of a match. He played in four Six Nations-winning teams, including two Grand Slams.
His death has stunned the world of rugby. France's rugby federation said the national sport was "in mourning after the tragic death of our wing Christophe Dominici".
It added: "We're particularly thinking of his family and loved ones."
A similar message came from the other big rugby union nations. The Welsh Rugby Union said: "Adieu, Christophe Dominici... what a player."
Former Stade Français president Max Guazzini, who was close to Dominici, told French radio he was deeply upset by the news. "I always told the others he was my favourite player," he said.
Ex-team-mate Vincent Clerc said: "I came up against him in the past and it was tough. You felt he had this passion to win."
Former Ireland captain Brian O'Driscoll described "a French player full of flair with huge success throughout his career".
Everyone in Irish Rugby is thinking of our friends in @FranceRugby following the desperately sad news of Christophe Dominici's passing.— Irish Rugby (@IrishRugby) November 24, 2020
We're thinking particularly of Christophe's family, friends and former team-mates at this sad time. May he rest in peace. 🇫🇷 pic.twitter.com/AiCMTqurm9
Earlier this year, Dominici was heavily involved in a bid by a consortium from the United Arab Emirates to take over the financially troubled Beziers rugby club in the south of France.
The bid was halted by the sport's financial regulator and Dominici was said by friends to have taken the failure very badly.
In a 2009 Le Monde interview, he said: "[Rugby] let me understand many things - respect for life, people and oneself, along with the values of humility and combat. I was aggressive and put that to collective use. Now I have far more wisdom and maturity."