The body of a man believed to have stowed away in the undercarriage of a British Airways plane was found on the roof of a building near London Heathrow Airport, authorities said Friday, according to UPI. The body of the man, whose name wasn't revealed, was discovered on the roof of a business Friday morning. Police said they're treating his death as unexplained, but they believe it may be connected to the discovery of a another man hiding in the landing gear of British Airways Flight 54, which arrived at the nearby airport about an hour before the dead man's body was discovered. The second man was hospitalized with injuries. The Boeing 747 took off Thursday night from Johannesburg and arrived Friday morning in London. The 5,600-mile flight usually takes around 11 hours to complete. Experts say hitching a ride in the wheel well of an aircraft is particularly dangerous. If the stowaway isn't crushed by the landing gear as it folds up after takeoff, subzero temperatures will often kill the unticketed passenger. Despite the danger, Jose Guillen, a ground operations coordinator at Chicago's O'Hare International Airport told CNN last year it's easy to get into the wheel well. 'You can grab onto the struts and landing gear assembly kind of like a ladder,' he said. 'And you just jump on the tire and climb into the wheel well.'