The father of a missing teen stabbed to death in Lee on Saturday, said he is baffled as to why anyone would want to hurt his son.
Kevin Ssali from Whitworth Road, South Norwood, was attacked at about 9.45pm after getting off a bus in Lee Green, in south-east London.
The 14-year-old was killed by a single stab wound to the heart.
Police are investigating whether an altercation on the 202 bus led to the fatal attack.
The teenager had been missing from the home he shared with his mum and younger brother for two months prior to his death.
His father Sewa turned 54 the day before the stabbing and had wished for Kevin's safe return as a birthday present.
Mr Ssali, who lives in Catford, said: "We are going through all the emotions, we have all the questions and no answers.
“I am absolutely baffled as to why anybody would want to do any harm to him. We don't know if it happened out of the blue or whether the person had a grudge against him."
Kevin, who dreamt of becoming a bank manager, was reported missing on July 13. An appeal was put out through charity Missing People.
While away the teen, who had never gone missing before, contacted his cousin on Facebook to let her know he was ok.
His brother Tim, 23, said: "He went missing the week before they broke up from school, but he was spotted at school on the last day of term.
"He messaged our cousin on Facebook a few times to say he was ok. The messages just said he was ok, they were short, no details, no contact, address or anything."
Tim said he sent Kevin numerous Facebook messages he was sure he read, but never received a response.
Mr Ssali, who is separated from Kevin's mum, said he had no idea why his popular son left home, or where or with whom he was staying, but would ask his cousin to pass messages on to him.
"Unfortunately I am not a Facebook person, but we would pass messages on to tell him 'we miss you' and to try and convince him to come home," he said.
"He had never left before and had never given any indication he was unhappy at home. He was like any other teenager, sometimes came home too late, but his mum took good care of him.
"There was nothing untoward, nothing that was there to indicate he meant to run away. We took it in our stride and wanted to get him back and find out what issues he had and get him back into education."
Kevin who was a pupil at Crown Woods College in Eltham, used to live along Lee High Road and may have been visiting a friend on Saturday, whose house was close to where he was killed.
Remembering his son, Mr Ssali said: "He has always been a popular young man; he was always going out with a different friend.
“He was a very nice boy and everybody who came into contact with him said he was very humble and polite. It is absolutely devastating.”
Mr Ssali said the family planned to set up a campaign in Kevin's memory to prevent other families from going through the same experience.
He added: "If I had the power to stop this happening to any other parent I think it would be my dying wish. We will do everything possible in Kevin's memory."