COMRADES of a Royal Marine from York who sent his friends on the trip of a lifetime after his death have told of his tragic final moments.

David Hart, of 40 Commando, was killed by a bomb blast while serving as part of Combined Force Sangin in Afghanistan's Helmand province in July 2010, a day before his 24th birthday.

Servicemen who were with him at the time told an inquest today of the explosion and the fight to save him. Captain Graham Smith said Marine Hart, from Poppleton, had been "extremely unlucky", stepping on an improvised explosive device (IED) that all his comrades had missed.

Marine Hart and 11 other British officers were following 13 soldiers from the Aghan National Army when the tragedy struck.

He was sixth in line in an "Afghan snake", single-file foot patrol when the bomb went off and he "disappeared underground", the inquest at New Earswick Folk Hall was told.

Captain Smith said the British officers were armed with metal detectors and were familiarising themselves with the area, having only arrived days before.

He said the officers set out at 6pm on July 8 and had been walking for about 20 minutes when he heard a "large explosion" behind him.

He said: "I turned around and there was a very large dust cloud which rose high into the air."

Captain Smith said a fellow Marine shouted "David is down, David is down", and there was a large crater where the explosion had happened.

Later investigations revealed it was an IED connected to three metres of cable and wired up to a battery pack, which acted as the detonator.

Because of the distance between the pack and the scene of the blast, the metal detectors had not picked up the IED.

First aid was administered and Marine Hart was taken to a nearby medical camp within eight minutes, but was pronounced dead at 7.12pm.

Marine Joel Oliver, also of 40 Commando, told the inquest he was leading the patrol when he heard a loud explosion.

He said that, after clearing the area around Marine Hart, he administered what first aid he could, but the marine had suffered severe injuries to his legs.

At the inquest, he told Marine Hart's parents Chris and Dilys Hart: "He was easily one of the best guys. I am extremely sorry he has been taken from you so soon."

Sergeant Damien O'Sullivan, of 40 Commando, who was marching behind Marine Hart, said: "There was a couple of seconds' pause - almost the shock, I guess - and somebody said Dave had been hit.

"There was nothing on that day that led us to believe that there was any particular threat.

He told Mr and Mrs Hart: "I knew Dave from when he joined. He was one of the most professional people I have ever met and he had a shining career in the Marines ahead of him.

"He was the life and soul of any situation and he was deeply loved and respected by everybody."

Marine Hart left £100,000 after his death for 32 of his friends to go on a dream holiday to Las Vegas, and instructed them in a letter to take the trip as "a last gift from me".

He also left £50,000 to the Royal Marines Charitable Trust Fund, which helps wounded and retired Marines, and a large sum to his family.

In a written statement read at the inquest, pathologist Dr Nicholas Hunt said: "He had died as a result of a devastating complexity of injuries to his lower limbs, pelvis and abdominals primarily.

"It was clear extensive efforts had been made to save his life."

He said Marine Hart would have been instantaneously unconsciousness as a result of the explosion and likely felt no pain. He gave a cause of death as blast injuries caused by an explosion.

York coroner Donald Coverdale said: "Quite a number of people had walked across this spot and unfortunately Marine David Hart walked across it and it was his footstep that triggered the IED."

His verdict was that Marine Hart died from injuries inflicted by an explosive IED while on active service in Afghanistan.

Marine Hart had studied horticulture at Askham Bryan College, and went on to become a landscape gardener for two years before deciding he wanted to become a marine.

At his funeral at York Minster, friends said he was a huge football fan who loved socialising and always had a "cheeky smile".