A man believed to have stowed away on a long-haul flight plunged to his death from te British Airways jet as it approached Heathrow Airport to land.
He reportedly clung on to the plane all the way from Johannesburg in South Africa - a journey of around 8,000 miles lasting over 11 hours.
The victim, who has not been identified, fell on to the roof of the business NotOnTheHighStreet.com in Kew Road, Richmond, south west London, yesterday morning.
Police and an ambulance were called just after 9.30am and found the man dead at the scene.
A second man, believed to be between 25 and 30, survived the dangerous journey and was found unconscious at the airport. He remains in a serious condition at a west London hospital.
A Scotland Yard spokeswoman said: "A post-mortem examination will be held in due course and inquiries are ongoing to establish the male's identity. No arrests have been made."
A British Airways spokeswoman said: "We are working with the Metropolitan Police and the authorities in Johannesburg to establish the facts surrounding this very rare case."
The airline said it could not comment further on the flight because police are investigating.
NotOnTheHighStreet.com said in a statement: "Officers and the London ambulance service attended and found the body of a male on the roof of the premises.
"The death is currently being treated as unexplained but early indications are that the body may be that of an airline stowaway."
They said the incident "is unrelated to the business or its team members" and they are co-operating with the ongoing police inquiry.
Reverend Neil Summers, from the St John the Divine of Richmond church opposite where the body was found, said he was "shocked" and would lead prayers for the dead man.
He told The Press Association: "It's shocking, you do not expect these things to happen on your patch really. In one sense it's not totally surprising as it's happened before.
"It's very shocking when it's so close to you. We are going to say prayers for the people concerned tonight."
This is not the first time that stowaways have fallen to their deaths from planes. Most die from freezing temperatures and lack of oxygen, but those who survive the conditions also face the danger of falling from the plane.
In September 2012, Jose Matada, 26, from Mozambique, died after falling from the undercarriage of a Heathrow-bound flight from Angola on to a quiet street in Mortlake, west London.
An inquest into his death heard he was believed to have survived freezing temperatures of up to minus 60C (minus 76F) for most of the 12-hour flight.
But it was believed he was "dead or nearly dead" by the time he hit the ground.