Leicester City's owner Vichai Srivaddhanaprabha, along with two members of his staff, the pilot and a passenger were killed in an aircraft crash just outside the King Power Stadium.
Worth an estimated $3.8bn, Srivaddhanaprabha bought Leicester in 2010 for £39m, paid off their debts and saw the club win promotion to the top league just 4 years later.
Leicester City then beat the odds of 5000-1 to claim the Premier League title in 2015-16 in one of the greatest sporting stories of all time.
Leicester City has released a statement following the death of 'Khun Vichai'.
Thousands of fans have also left flowers and scarves outside the stadium.
The football world is also in mourning over the passing of the great man.
We're thinking of you, @LCFC ❤Our deepest condolences are with the loved ones of those who have so tragically lost their lives, and everyone at #LCFC— Arsenal FC (@Arsenal) October 28, 2018
Sending our heartfelt condolences to the families of those who tragically lost their lives and to everyone at @LCFC. We are all thinking of you during this difficult time.— Tottenham Hotspur (@Spurs_India) October 28, 2018
Everyone at #MUFC is deeply saddened to learn that the Leicester City chairman and four fellow passengers have lost their lives following last night's tragic incident. Our deepest condolences are with their families, friends and those connected to the club.— Manchester United (@ManUtd) October 28, 2018
The thoughts of everyone at Liverpool Football Club are with Leicester City and those affected by events at the King Power Stadium this evening.— Liverpool FC (@LFC) October 27, 2018
Footballers associated with the team who knew Srivaddhanaprabha also expressed their sorrow.
Struggling to find the right words....but to me you are legend, an incredible man who had the biggest heart, the soul of Leicester City Football Club. Thank you for everything you did for… https://t.co/FzTaXVejUg— Jamie Vardy (@vardy7) October 28, 2018
Leicester City Goalkeeper Kasper Schmeichel, who was especially close to Srivaddhanaprabha also released a statement.
The game of football will always remember you, Vichai Srivaddhanaprabha. Your contributions to the game will go down in history. RIP.