The body of a man believed to have been a stowaway who fell from the undercarriage of a jet approaching London’s Heathrow Airport has been found in a garden in the city’s south end, police said Monday.

The man fell from the landing gear of a Kenya Airways plane as it approached London after a nine-hour flight from Nairobi, according to police and airline officials.

Metropolitan police said the body of an unidentified man was found in a residential garden in the city’s Clapham district on Sunday.

The man has not yet been identified. Police said a post-mortem would be held to determine the cause of death.

‘Unfortunate’ incident: Kenya Airways

Kenya Airways said police traced the body to its Nairobi-London flight. A bag, water and food were discovered in the plane’s landing-gear compartment after the aircraft touched down.

The airline called the death “unfortunate” and said it was co-operating with British and Kenyan authorities.

Stowing away in a plane’s undercarriage is exceptionally dangerous. Experts believe roughly three-quarters of stowaways do not survive because of the extreme cold and lack of oxygen at the plane’s cruising altitude.

Though not common, stowaways have in the past plunged to the streets of London as planes lowered their landing gear.

In September 2012, a 30-year-old from Mozambique, Jose Matada, died after falling from the undercarriage of a Heathrow-bound flight from Angola.

Then, in 2015, a man was found in critical condition after stowing away in the undercarriage of a plane that travelled 10 hours from Johannesburg to London.