Russian news reports say a 20-year-old chess champion, Yury Yeliseyev, fell to his death from the 12th floor of a Moscow apartment building.
Multiple reports cite a friend of Yeliseyev's, Daniil Dubov, who wrote on the social network VKontakte that the young chess grandmaster fell while trying to climb from a window onto a balcony.
"Tonight my close friend [Yury] Yeliseyev, a brilliant chess player and analyst and one of the most talented people I know, died tragically," a post on Dubov's VKontakte page early on November 27 said.
There was no immediate comment from police.
Tabloid news site life.ru reported that Yeliseyev was apparently a devotee of parkour, an extreme sport whose practitioners use buildings as obstacle courses, scale walls and leap from rooftop to rooftop.
Yeliseyev won a world youth chess championship in 2012, and had been a Russian champion in classical chess in the 16-and-under category, state-run Russian news agencies RIA and TASS reported. They said he was ranked 212th by the World Chess Federation (FIDE).