They were only 100 yards away from the compound when the terrorists reportedly heard a dog bark – prompting the militants to shoot the pair dead.
Two medics involved in the operation tried to revive both of the hostages, but one died at the scene while the other succumbed to his injuries on the operating table inside the USS Makin Island.
Outgoing U.S. Defense Secretary Chuck Hagel confirmed Mr Somers death this morning as he landed in Afghanistan.
During a press conference he announced that 1,000 more US troops than expected will be stationed in the country next year following a spike in Taliban attacks.
Mr Somers was badly wounded when commandos found him and he died from his injuries by the time he had been flown to a naval ship.
Mr Somers’ sister Lucy Somers told Associated Press that she learned of her brother’s death from FBI agents at 5am this morning. ‘We ask that all of Luke’s family members be allowed to mourn in peace,’ she said from London.