On Saturday evening, a helicopter carrying Leicester City owner Vichai Srivaddhanaprabha and four other passengers crashed shortly after take-off, killing everyone on board.
The incident, which happened just over an hour after the Foxes had secured a 1-1 Premier League draw with West Ham, has stunned the footballing world and left the 2015-16 English champions in a state of shock.
Tributes have poured in for those who lost their lives in the incident, with former Leicester star Riyad Mahrez dedicating the winner he scored for Manchester City against Tottenham on Monday to a man he described as “such a good human”.
Questions have naturally arisen as to how tragedy struck and what exactly caused the incident, and while an investigation is already underway, it could be months before an answer is delivered.
What could have caused the Leicester helicopter crash?
The Air Accident Investigation Branch (AAIB), which is the body that looks into civil aircraft accidents in the UK, was on the scene shortly after the crash to begin its investigation into the incident.
It has deployed inspectors who will cover the four accident investigation disciplines of engineering, operations, flight data and human factors.
The AAIB has confirmed that it has recovered the flight data recorders from the wreckage and the inspectors began studying the recorder on Monday. It also revealed that it was “subject to intense heat as a result of the post-accident fire”.
"The engine stopped and I turned round and it made a bit of a whirring noise, like a grinding noise," freelance photographer Ryan Brown told BBC Radio Leicester.
"The helicopter just went silent, I turned round and it was just spinning, out of control. And then there was a big bang and then [a] big fireball."
Speaking to the BBC, Jim Rowlands, a former RAF Puma crew member, said that he believes the incident was caused by an issue with the tail rotor, which prevents the helicopter from spinning around.
"If you lose your tail rotor it's almost impossible to recover from," he said.
"You can't get out of it. It would be more luck than judgment if you were to survive.
"It could have been a human factor, it could have been pilot error or poor maintenance that led to something."
While Rowlands admitted that his “gut feeling” was a mechanical issue, he added that there were “so many things it could have been”.
Speculation that a police drone might have been the cause of the crash has been put to bed, however, by Leicestershire Police, who revealed on Twitter that it was not in flight at the time.
The AAIB has appealed to witnesses who have videos or photographs of the crash to contact Leicestershire Police.
It was later reported by Sky that investations found that the crash was caused by a pin that had come loose in the tail rotor control mechanism, resulting in the helicopter becoming unstable and preventing the pilot from being unable to control it.
Further investigations into the incident showed that the pilot's pedals became loose from the tail rotor, causing the aircraft to make an uncontrollable right turn before immediately spinning and falling, crashing into the ground in flames.
There was a "build-up of black grease" on one componenent of the mechanism linking the pedals and tail rotor, causing it to become disconnected.
When will the cause of the Leicester helicopter crash be known?
It could take many months to discover the exact cause of the crash due to the painstaking nature of the investigation that the AAIB will have to undertake.
“The site phase is only the start. Once everything has been documented and photographed, and witnesses have been contacted, the wreckage is usually recovered and transported to our facility in Farnborough,” it explained.
Once in Farnborough, the wreckage is studied in detail, which involves various tests and can even include flight simulator sessions.
“This phase of an investigation can take several months for an accident involving a light aircraft and potentially more than a year for a major accident,” according to the AAIB.
However, a ‘special bulletin’ from the organisation is released within a month of a major accident investigation to provide details of initial findings.
The full report on the crash will, however, only be published when the AAIB is satisfied it has done all it can to ascertain the cause of accident and it will not put a timeframe on how long that may take, though they are optimistic it will be under a year.
“When we have analysed the evidence, drawn conclusions and are making safety recommendations, a draft report goes through several stages of internal review within the AAIB,” it said.
“We are then required to issue a confidential draft report to those that have been involved in the investigation and also those whose reputation may be affected by our report.
“Under the UK regulations this consultation lasts for 28 days.
“Representations made by those consulted are given due consideration before the publication of the final report.
“Most field investigation reports are published within 12 months of an accident occurring.”