Sunbather nearly crushed as frozen stowaway falls down 3,500 ft out of Kenya Airways jet's landing gear in London

A stowaway fell from the undercarriage of a jet as it approached Heathrow Airport after a nine-hour flight from Nairobi and landed in a south London garden, police and airline officials said Monday.

The Metropolitan Police said the body of an unidentified man was found in a residential garden in south London's Clapham area on Sunday, and it's believed he fell from a plane.

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

The airline called the death "unfortunate" and said it was cooperating with British and Kenyan authorities.

John Baldock, a software engineer in his 20s, was sunbathing in his back garden when the corpse fell from the plane's landing gear just yards away and shattered a path, leaving a sizeable crater in the lawn.

Baldock immediately fled from the £2.3m ($2.9m) four-story house in Croydon, south London, to stay with his parents in Exeter, Devon.

“I was in the kitchen and there was a huge noise. It shook the kitchen. I thought my house was falling down," a neighbor told The Sun.

"I went upstairs and looked out the window and saw the body. John had been out sunbathing. He is a lodger with and friends with Bob the owner."

"[John] was shaking and trembling," she continued. "He wasn't saying anything. He could hardly speak. My husband called the police. It was horrific."

Another neighbor recounted the incident: "I heard a 'whomp'—I went upstairs to look out of a window. At first, I thought it was a tramp asleep in the garden. He had all of his clothes on and everything. I had a closer look and saw there was blood all over the walls of the garden. His head was not in a good way. I realized immediately that he had fallen."

According to flight tracking data, the 4,250 mile trip from Nairobi to Heathrow takes about eight hours and 50 minutes, which meant the stowaway would have had to survive most of the duration starved of oxygen and temperatures around -60C (-76F) at an altitude of 40,000ft.

That said, the passenger jet was flying at just over 3,500ft and a speed of 200mph as it passed over Clapham when the corpse fell from the landing gear.

Cops discovered a bag, water, and food in the plane's landing-gear compartment after it landed. They are now working to establish the corpse's identity.

“At this point, police believe the man was a stowaway and had fallen from the landing gear of an inbound Kenya Airways flight to Heathrow Airport," Scotland Yard said in a statement.

"A bag, water, and some food were discovered in the landing gear compartment once it landed at the airport. Inquiries continue, led by the South Central Command Unit and the Met's Aviation Policing Command. Officers will be liaising with the airline and international 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 as the plane reaches 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.

The Associated Press has contributed to this story.