A man is believed to have plummeted over 1,000 feet to his death after spending 11 hours inside a plane's landing gear.
According to The Guardian, the body was found on the roof of a west London building that houses online retailer Notonthehighstreet.com at around 9:30 am on Thursday.
Authorities say he and another man hid in the wheel compartments of a British Airways flight that left Johannesburg, South Africa Wednesday night and flew 8,000 miles to Britain's Heathrow Airport.
The Boeing 747 was roughly 1,400 feet in the sky when it passed over the office building.
It is not clear if the man died before the fall or by impact.
The second man was found unconscious inside the plane shortly after it arrived at Heathrow, which was at least an hour before the dead body was reported.
He is thought to be 24 years old, and is currently hospitalized in critical condition.
Both British Airways and Airports Company South Africa, which runs the Johannesburg airport, described the incident as "very rare."
This at least the third time, however, in which a man has died trying to smuggle himself onto a British Airways flight within the past few years.
A stowaway froze to death while hiding in the undercarriage of a flight from Turkey to Heathrow in July of 2013, Daily Mail reports.
José Matada somehow survived temperatures as low as -76 degrees Fahrenheit and severe oxygen deprivation during a 12-hour trip from Angola, Africa to Britain in September of the previous year.
But the 26-year-old was barely clinging to life and died before he fell from the aircraft onto a west London street.
Consulting editor of Flight International magazine David Learmount believes the surviving stowaway from the recent incident sneaked into the plane's cargo section.
I don't see how anybody can survive 11 hours at 35,000 feet and at less than -50C. I don't think we can assume these two men were at the same part of the plane.
Access to a heated area, Learmount said, is the only way to survive such conditions.
Citations: Stowaway fell to death from plane on to London office after 8000 mile flight (The Guardian), Stowaway falls to his death from jet as it approaches Heathrow after 11 hour journey from South Africa but second SURVIVES (Daily Mail)