The Leicester City owner's helicopter has crashed in a auto park outside the club's ground as it left the stadium following a Premier League match.
He is regularly picked up from the stadium by his chopper, which lands on the centre circle before taking off after the full-time whistle.
The helicopter got into trouble at a height of around 200 feet.
"It could have crashed where I was, in auto park E, it could have crashed into the building".
The website Planefinder said that Mr Srivaddhanaprabha's Agusta Westland AW169 helicopter set off from near Fairoaks Airport in Surrey at about 2.45pm on Saturday, and travelled into Fulham, west London, before turning north and proceeding to the King Power Stadium in Leicester.
The club said it was assisting police and emergency services and would issue a more detailed statement in due course.
And while pumping tens of millions of pounds into the team, club infrastructure and reducing debt, Vichai spent judiciously.
"From knowing you we do this by being the family you created".
Another witness said it appeared "the tail propeller wasn't working, putting it into a spin".
"The helicopter just went silent, I turned round and it was just spinning, out of control".
"Without you and your family, all this, everything we did together, everything we achieved, would never have happened". Everyone is in utter shock.
"We extend our deepest sympathy to Mr Srivaddhanaprabha's family and friends, and to Leicester City at this sad time".
Among the tributes was an image of Ganesh - a Hindu god also seen in Thai Buddhist temples. Hours before the Sunday night confirmation that Vichai did not survive the crash, scarves, jerseys and flowers were laid in an ever-expanding memorial in front of the stadium.
Leicestershire Police said in a statement: "Five people are believed to have died when a helicopter crashed outside the King Power Stadium yesterday evening (Saturday 27 October)".
It was regarded as one of the greatest underdog stories in the history of sports. Vichai has formed a close bond with the fans, sometimes mingling with them at games, in contrast to some Premier League owners who maintain a distance.
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"The Air Accidents Investigation Branch (AAIB) is leading the investigation into the accident and a cordon remains in place at the scene while enquiries continue".
"A cordon is now in place at the scene to enable the AAIB to examine the area and complete their initial enquiries". Leicester's nickname is The Foxes.
The EFL (English Football League) said Leicester City's round-four Carabao Cup tie with Southampton, scheduled for Tuesday, had been postponed because of the incident.
"He's put Leicester on the map", club supporter Cathy Dann, 55, told AFP.
It was under Vichai's ownership that Leicester crafted one of the biggest fairytales in English football history by winning the 2015/16 Premier League, having started the season as 5,000-1 outsiders for the title.
It said the 60-year-old, who bought the club for £39 million in 2010 and led it to a first Premier League title in 2015-16 was a "great man".
In 2017, he had also bought a football club in Belgium, Oud-Heverlee Leuven.
The Foxes have been unable to reach the same meteoric heights since, finishing 12th in the following season and ninth in 2017-18.
Vichai's investments in the club helped return them to the Premier League from the second-tier Championship in 2014.
There, Leicester City defied the odds yet again, winning their group before eventually losing their quarter-final 2-1 over two legs to Atletico Madrid.
But not even their most devout fans could have imagined what happened next.
Fans were treated to a free beer to celebrate his birthday ahead of a match against Newcastle in April this year.
"He said, I think two or three years before, that he wants the team to be a success in the Premier League, and now we are". The name means the "light of progressive glory".
While Vichai did not seek the limelight and was far from flamboyant, the wealthy entrepreneur's grandiose mode of transport from the King Power stadium named after his duty-free empire became symbolic of the club's newfound status in the game.