Millwall’s owner and chairman John Berylson dies at the age of 70 following a “tragic accident”, the club announce.
The American businessman first became involved with the Championship club in 2006.
“He was a truly great man, incredibly devoted to his family,” Millwall said in a statement.
Berylson is survived by wife Amy and his three children Jennifer, James, and Elizabeth.
The club added: “He was a person of such remarkable generosity, warmth, and kindness.
“He lived a storied life, one full of colour and joy, and was infinitely thoughtful of others with an endless desire to share his immense knowledge and experiences to help people.”
Millwall have not released any further details around Berylson’s death.
The club have said fans can pay their respects in a book of condolence which will be shared with his family.
Supporters can write in the book at the club’s The Den stadium on Wednesday from 11:00 BST, or online.
“He has presided over some of the greatest moments in Millwall’s history, and his influence in providing the platform for those was immeasurable,” the club said.
“John continued to speak eagerly about the new season and his vision for the future, and any success moving forward will be in his memory and honour. It will be his legacy.”
Millwall finished eighth in the Championship last season, just missing out on a play-off place on the final day.
Berylson became a significant shareholder of the club in 2007 after he led a consortium who invested in the then League One side.
He replaced Stewart Till as chairman in the same year and went on to oversee two promotions into the Championship.
The last promotion came in 2017 and the club have maintained their position in the second tier ever since.
‘A chairman and friend’
Tributes have poured in for the owner with former Millwall right-back Alan Dunne saying: “My deepest condolences to not only my chairman for many years but also friend.
“John was a gentleman who put Millwall back on the map. What he has done for the club will always be remembered and can only thank him for everything he done for me and MILLWALL.”
Aberdeen’s chief executive Alan Burrows said: “Such awful, awful news. The thoughts of everyone at Aberdeen FC are with John’s family, friends and everyone at Millwall FC. RIP.”
The English Football League wrote: “The EFL is shocked and saddened by the news and sends its deepest condolences to John’s family and everyone connected with Millwall.”
Multiple clubs have sent their condolences, including rivals West Ham, who wrote: “Everyone at West Ham United sends their deepest condolences to John’s family, friends and all at Millwall FC during this tragic time.”