The flight data recorder recovered from the helicopter that crashed with the Leicester soccer team's owner on board is being examined by investigators, authorities said Monday.
Thai retail entrepreneur Vichai Srivaddhanaprabha and four other people were killed in Saturday's crash outside the King Power Stadium following a Premier League match.
The aircraft spiralled out of control and burst in flames.
Aiyawatt Srivaddhanaprabha, Vichai's son, brought a wreath on Monday to add to a collection of flowers, jerseys and club memorabilia that was growing two days after the disaster.
Inspectors are expected to remain on site until the end of the week, when the wreckage is to be transported to specialist facilities for a detailed examination, the Air Accidents Investigation Branch said.
Experts with specialties in engineering, operations, flight data and human factors are working on the investigation.
"We recovered the digital flight data recorder (voice and data) on Sunday afternoon and one of our inspectors travelled back to Farnborough with the recorder the same evening," the AAIB said in a statement.
"Today, our inspectors in Farnborough will start working on the recorder, which was subject to intense heat as a result of the post-accident fire."
Police have not provided an update on the investigation, but wrote on Twitter its drone "was not in flight at the time the helicopter left the stadium."
"I was lucky to have known Vichai for several years," said Prince William, the second-in-line to the British throne. "
He made such a big contribution to football, not least through Leicester City's magical 2016 season that captured the imagination of the world."