Two Cuban schoolboys who died when they stowed away in an airliner's wheel bay had taken the wrong plane, an inquest heard today.

They slipped unnoticed in to the wheel bay of a BA flight from Cuba to Gatwick, "fell asleep" and died as the jet soared to 37,000ft, an inquest heard today.

Maikel Almira, 16, who left a note for his mother saying he was going to America to find work, was found in a field close to Gatwick airport on Christmas Eve.

Alberto Rodriguez, 15, who is also believed to have clambered into the wheel bay of the same BA aircraft from Havana to Gatwick, was seen falling from the jet as it took off next day from the West Sussex airport.

An inquest at Haywards Heath saw a police video of the BA Boeing 777, which showed foot marks on the inside of a wheel bay flap.

It is thought the pair may have frantically tried to hang on to the jet as it took off from Havana's Jose Martin airport at midnight on Christmas Eve.

Pathologist Colin Hunter-Craig, who carried out a post-mortem examination on Alberto, told the court that the boys would have died minutes after take-off as oxygen levels plummeted.

He said both boys suffered injuries consistent with a fall but would have died after slipping into unconsciousness. He said: "I surmise they died on the way up. This aircraft climbed to 37,000ft in 20 minutes. That's higher than Everest.

"Some climbers can reach the top of Everest without oxygen but they adjust slowly. If you go up as suddenly as these boys did you don't have time to adjust. They died through lack of oxygen or hypoxia.

"They would have just fallen asleep. They would not have been aware of what was going on. To be whipped up that high so fast would be disastrous."

Det Sgt Mick Jones of Sussex Police, who went to Havana to formally identify the boys, read statements from their parents who said the boys were close friends.

The inquest heard the boys had planned to board a different flight from the airport which was bound for Miami but, due to delays, boarded the wrong plane.

Det Sgt Jones told the court the flight to Miami was "survivable" for a stowaway in the wheel bay of a jet.

It is thought the boys had planned to fly to Miami to visit Alberto Rodriguez's grandfather. The plane they had intended to smuggle on board was delayed to allow the Gatwick-bound BA flight to leave.

The detective said: "The BA flight was given priority to leave before the outbound flight to Miami. It was also a Boeing 777. We believe the boys boarded the wrong aircraft.

"We have been told the flight to Miami is a survivable one but still poses enormous risks."

The jury returned a verdict of accidental death.