Corporal Will Rigby will never forget his 24th birthday. It was the day he held his identical twin's hand for 10 hours and watched him die.
Corporal Will Rigby, right, with his twin, Corporal John Rigby
Both brothers had been serving in Iraq when on 22 June, John, also a corporal, was seriously injured in a roadside bomb in southern Iraq.
He was taken to Basra military hospital but the prognosis was bleak.
Will first knew what had happened when he was woken by his platoon commander.
He hastily packed a few things and was flown to the hospital.
"Once I was shown the CAT scans... I knew it was only a matter of time before John was going to leave us," Will told BBC Radio 4's Today programme.
The brothers from Rye, in East Sussex, were both in the 4th Battalion The Rifles.
Although working in different teams, they were able to catch up over a cup of tea several times a day.
Will spent the next 10 hours at John's bedside, with some close friends, reminiscing about old times and even sharing the odd joke.
Corporal John Rigby suffered serious head injuries
"I'm certain he was hearing what I was saying and was with us at the time," says Will.
Every half hour, Will would call his father, Doug Rigby, back in the UK to update him on John's condition.
"It's a great comfort to me to have been by John's bedside when he passed away," says Will.
"I came into this world with John and 24 years to the day, he left us."
For his father, it was a very different experience.
"Two Army personnel arrived at the gate - we live in a very remote location. In an odd way, I had been half expecting it. I absolutely cannot explain why.
"They came in, we drank tea and I smoked more than I should have done, in a state of complete bewilderment."
"John was very, very special.
"He was an absolutely cracking bloke - everybody thought so. As a son, absolutely tremendous."
Corporal Will Rigby follows the coffin at his brother's funeral
Now Doug Rigby is facing the prospect of his other son, Will, returning to Iraq, where John became one of the 163 UK troops so far killed in Iraq.
"We are steeled for the possibility he will go back.. and we will support him."
For Will, it has been a decision requiring a great deal of thought.
"It became very apparent to me and John when we arrived the good that the British soldiers are doing in Iraq.
"As soldiers on the ground, we are making a difference, slowly but surely, to the people of Iraq.
"I have a job to do and I am a serving soldier. Where they say, I go. When I feel ready, I shall go back."