Garry Kasparov @Kasparov63
Very sad news. Jan was a friend of mine and a dear friend of chess. He co-founded the Kasparov Chess Foundation Europe and used his passion and expertise to promote the game and its benefits. — PolitiTweet.org
Grand Chess Tour @GrandChessTour
We are saddened to share the news that Jan Callewaert, the sponsor and organizer of the Your Next Move Grand Chess… https://t.co/ZeKGku6Z7v