It took around 30 hours for emergency teams to be able to reach Philip Goodeve-Docker's team and airlift them to safety but Mr Goodeve-Docker died before their arrival.
The London events manager was on the unsupported crossing with experienced expedition leader Roan Hackney and Andy Norman, a former IT professional, who both remain in a "critical condition" in hospital.
More top news
The twins cubs, which were born in June, have been named Bert and Ernie after characters from Sesame Street.
The two victims died from their injuries in hospital after the explosion in Hertfordshire.
Investigations are continuing into the cause of the crash in chigwell which killed both people on board.