The family of a student killed in the Malaysia Airlines MH17 crash have told how they waved him off at departures and "never saw him again".
Ben Pocock, 20, from Keynsham, Bristol, was a second-year international business degree student at Loughborough University.
He was "so excited" to be flying out to begin a professional placement and study abroad at the University of Western Australia in Perth as part of his third year.
All 298 people on board the flight, from Amsterdam to Kuala Lumpur, died when the jet was shot down over an area of Ukraine controlled by pro-Russia separatists on July 17.
Earlier this month, more than 500 mourners packed into St John's Church in Keynsham to remember the "sociable, likeable and talented young man".
In their first interview since Mr Pocock's death, his father Jeremy and sister Emily spoke about their pain at still not knowing what had happened.
Mr Pocock told BBC Newsnight he and wife Louise had taken their son to Bristol Airport to catch his first flight at about 3.15am.
"He was just so excited, even though it was an unearthly hour he just wanted to get on with it," Mr Pocock told the programme.
"We got to Bristol Airport and we sorted out his tickets and I think his Mum would have quite liked to have had a last minute cup of coffee with him before he went off but I could see that he was just so impatient, that he just wanted to get off into the departures lounge.
"And so we said our goodbyes, we had a hug, and that was it. We watched him go off into departures and that was it - we never saw him again."
Mr Pocock said he discovered news of the crash after checking Twitter on his phone as he returned home.
"It said a Malaysia Airlines flight had crashed and I just knew, in that second, that it was his," he said.
"Even though I couldn't quite recall the flight number I just knew immediately that it was his flight."
Mr Pocock said his family were desperate for answers over what had happened and who was responsible.
"The most important question for me, and for my family and for all the other families I should imagine, is what happened and who did it, i n very, very simple terms.
"They should be held to account. That's it, that's the bottom line."
He told the programme the family had been informed a few days ago that more than 700 fragments of human tissue or bone have yet to be identified.
The process is expected to last until next April or May, with many families receiving news of more identifications of their loved ones.
"We may be one of them," Mr Pocock added.
Tributes to Mr Pocock were paid following his funeral at the historic town centre church on December 1.
Graham Marsh, chairman of St Mary Redcliffe Cricket Club said Mr Pocock had been part of the club from a "very young age".
"Ben was a very sociable, likeable and talented young man who was so sadly taken from us at such a young age," Mr Marsh said.
His coffin was carried in and out of the church by friends and family, accompanied by white floral tributes reading 'Ben' and 'Friend'.
An order of service featured photographs of Mr Pocock as a child, teenager and young man.
He was shown beaming at the camera clutching a sporting trophy, playing cricket and tennis, in a swimming pool and striking a Usain Bolt pose.
Andrea Arlidge, headteacher of Wellsway School, which Mr Pocock attended, said the sportsman would be sorely missed.
"Ben was a delightful young man who was bright and talented at sport," Mrs Arlidge said. "We have wonderful lasting memories of him."
Mr Pocock had been on track to secure a first-class degree and had won a bursary to help with his travel costs to Australia.
The victims of the crash included 10 Britons, 43 Malaysians and 195 Dutch nationals.
Mr Pocock and his daughter Emily's interview will be featured on BBC Newsnight at 10.30pm tonight.