The father of a 19-year-old killed by a Tube train said his son's death was a "pointless waste of life".
Daniel Elgar, pictured with his girlfriend, was described as artistic
Daniel Elgar, from Southend, Essex, who had a five-month-old baby, died when he was hit by the train on Friday night, apparently after spraying graffiti.
He and Bradley Chapman, 21, from Grays, Essex, who was also killed, ran into the path of a District Line train at Barking station depot in east London.
Police have said the deaths highlight the dangers of trespass on the railway.
Mr Elgar's mother Vanessa wept as she told BBC London News: "He was one in a million and he really meant well. I love him and I miss him all the time."
His father Keith said: "It's something that's just a pointless waste of life."
Mr Elgar told how his son had been "artistic" at school.
"It was one thing he was good at - drawings and paintings. But I can only describe that maybe that's all a bit safe and maybe at his age he needed something that gave him some sort of risk factor.
"But we have got a memory now of Dan just on a dark grimy railway track."
He urged other "graffiti artists" not to go out and spray tributes to their son.
"We don't want anyone else at risk and if there's other lads out there thinking they'll pay a tribute - have a drink on him or meet together but there is no need to kill yourselves over it is there?"
He added: "I can't understand dying spraying a railway track that's just going to get scrubbed off anyway."
Mr Elgar's girlfriend Jodie Shea urged others: "Stay off the railway line."
They believe members of the graffiti gang fled after being shouted at by security staff who spotted them.
Bradley Chapman's mother Jackie told BBC London News that her son loved his family very much.
'Not worth it'
"He loved me and he'd do anything for me," she said.
"The only thing I could not get him to do was to stop spraying."
She said he fell back in with old friends spraying graffiti after he broke up with his girlfriend but did not necessarily want to get back into "that world".
But when they last spoke he told her he was no longer spraying graffiti.
She added: "The only thing I ever worried about was if he was arrested. I never thought of the danger."
Bradley's mother told others thinking about spraying graffiti on railway lines: "Please don't do it, it's not worth it. If they only knew the pain."
She said she could not bear it if anyone got killed paying tribute to her son by spraying graffiti where he died and urged others not to do it.
Officers, who believe there were four young people in the gang, arrested two men aged 23 and 25 following the incident, on suspicion of causing criminal damage. They were later bailed.
On Saturday, Chief Superintendent Paul Crowther said initial inquiries showed the gang had not been chased by the security guards.