Story highlights The plane was flying from Johannesburg to London 
 
 A second man, who was hiding in the undercarriage of the plane, was injured 
 
 (CNN) A stowaway on a British Airways jet was found dead after falling on a roof as the plane approached London Heathrow Airport, authorities said Friday. 
 
 It's unclear whether the man had crouched in the wheel well, a common hiding place for stowaways. 
 
 A second man who was hiding in the undercarriage of the plane was hospitalized with injuries, the airline said. 
 
 The plane was flying from Johannesburg to London when the man fell and landed above a business in Richmond, southwest London. Johannesburg and London are about 6,000 miles apart, and the flight is nearly 12 hours long. 
 
 Airline tracking website FlightAware.com lists British Airways Flight 54 as a Boeing 747. It departed Johannesburg on Thursday night and arrived at Heathrow at 7:26 a.m. London time Friday. 
 
 Read More ||||| LONDON (AP) — A man is in critical condition in a London hospital after he was found stowed away in the undercarriage of a plane that had just completed a 10-hour flight, and police are investigating whether a man found dead on a west London rooftop had fallen from the same plane. 
 
 Authorities at Heathrow Airport found the man in the undercarriage of a British Airways plane after it landed Thursday morning on a flight from Johannesburg. Police say they believe they know his identity and that he is 24 but they are awaiting confirmation before they release any details. 
 
 While there is no evidence to link the two cases, police say they are looking into whether there is a connection to the body found an hour later in the west London community of Richmond, which is below the flight path. 
 
 British Airways said it is working with police in London and Johannesburg to establish the facts in this "rare case." 
 
 Experts believe roughly three-quarters of stowaways do not survive if they hide on a plane's undercarriage because of the extreme cold and lack of oxygen they experience as the plane reaches cruising altitude. Though not common, stowaways have in the past plunged to the streets of west London as the 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 on to a street in Mortlake, which is not far from where the body was found Thursday. 
 
 An inquest into his death suggested he had survived freezing temperatures of up to minus 60 Celsius (minus 76 Fahrenheit for most of the 12-hour flight, but he was believed to be dead or nearly dead by the time he hit the ground. 
 
 Aviation expert Chris Yates described the latest situation as unusual because of enhanced security measures at airports meant to deter terror and other attacks. However, he noted that the stowaways who survive have tended to be young people. 
 
 The Rev. Neil Summers, from the St John the Divine of Richmond church across the way from where the body was found, said he would lead prayers for the dead man. 
 
 "In one sense it's not totally surprising as it's happened before," he said. "It's very shocking when it's so close to you. We are going to say prayers for the people concerned tonight." ||||| A stowaway has fallen to his death after clinging to the bottom of a British Airways jet as it flew over London. 
 
 The man is believed to have plunged from the aircraft and on to the offices of a clothes business in Richmond, south-west London. 
 
 A second man is in a serious condition in hospital after being found unconscious at Heathrow. 
 
 The pair are said to have held onto the plane as it flew more than 8,000 miles from Johannesburg in South Africa to Heathrow.
– Two stowaways clung to a British Airways passenger jet on its 6,000-mile journey from South Africa to London, but police say only one survived the trip, NBC News reports. The plane was 11 hours into its flight and preparing to land at Heathrow Airport yesterday when one of the stowaways fell out of the plane and onto the roof of a London clothing store. CNN notes it's unclear whether the victim was hiding in the plane's wheel well, but that's a common refuge for stowaways, who often don't survive there because of the reduced atmospheric pressure and freezing temperatures when the plane is high in the sky, NBC notes. "We are working with the Metropolitan Police and the authorities in Johannesburg to establish the facts surrounding this very rare case," a British Airways rep tells ITV News. The surviving stowaway, who CNN notes was found in the plane's undercarriage, was reported to be in serious condition at a local hospital, per NBC. The AP notes that stowaways have plunged onto the streets of west London before: In September 2012, the body of a 30-year-old from Mozambique was found on a street near where yesterday's incident occurred; he had been traveling in the undercarriage of a Heathrow-bound flight from Angola. (A teen stowaway survived in a plane's wheel well from California to Hawaii by entering a "hibernation-like state.")