Former England footballer Ugo Ehiogu has died at the age of 44.
Ehiogu, who worked as under-23 coach for Tottenham Hotspur, had been taken to hospital after suffering a cardiac arrest at the club's training ground on Thursday.
On Friday morning, Tottenham wrote on Twitter: "It is with immense sadness that we announce the passing of Ugo Ehiogu, our Under-23 coach."
The former Aston Villa and Middlesbrough defender collapsed and was treated at the scene before being taken to hospital by ambulance.
His wife Gemma and young son had rushed to the hospital to be with him.
However, the 44-year-old passed away in the early hours of Friday morning.
John McDermott, Tottenham's head of coaching and player development, described Ehiogu as "irreplaceable".
Tottenham midfielder Joshua Onomah wrote: "Way more than just a coach, a father figure as well! Done so much for all of us boys. RIP Ugo. See you soon."
Ehiogu had been at Spurs since 2014, but began his career as a trainee at West Bromwich Albion before moving to Aston Villa in 1991.
He went on to feature in more than 300 matches for Villa over a nine-year spell, winning the League Cup in 1996.
After joining Middlesbrough for a then club-record £8m fee, he won the same trophy with the northeast club in 2004.
Capped four times by England, he also played for Leeds, Rangers and Sheffield United before retiring in 2009.
Aston Villa wrote on Twitter: "We are deeply saddened to hear of the death of our former defender Ugo Ehiogu. Our thoughts are with his family at this terribly sad time."
They will hold a minute's applause before their derby with Birmingham City on Sunday and both sets of players will wear black armbands as a mark of respect.
Aston Villa's manager, Steve Bruce, paid tribute to the footballer in a press conference, saying: "I played against him. Big Ron bought him for £45,000 - what a bargain. He was a great player."
Former striker Stan Collymore, who played with Ehiogu at Aston Villa, posted a photo of the pair on Twitter, writing "One of the good guys. Truly broken."
Former England player Rio Ferdinand wrote: "Can't believe the news that Ugo Ehiogu has passed away. Calm & warming vibe when in his company. My heart goes out to his family! #RIPUgo."
Sky Sports journalist Adam Lindsay wrote on Twitter: "Humans do not come much better than Ugo Ehiogu. RIP."
Ehiogu wrote his last message on his Twitter page three weeks ago, when he shared an impulsive good deed with his fans.
"Gave a homeless girl £10 last night in Dalston. She didn't ask or beg. Random impulsive act from me. Not gona lie. Felt good. #dosomethingkind".