Connor Marron (19) “walked in the shadow of his father” and was a popular member of his local Roger Casements GAC in Portglenone, according to club secretary Martin Kearney.
He was described as a multi-talented sportsman, having had success in Gaelic football, snooker, pool and soccer in his youth.
The second-year Ulster University student was hit by a train between Alexandra Palace and Finsbury Park at 12.53am on Monday, according to Great Northern Rail.
The company added the line reopened at 2.24am following the “tragic incident”.
Connor was under-16 Northern Ireland snooker champion at just 12, and was well-known at Red’s Sports Lounge in Ballymena.
Member Gary Clarke said in a Facebook post: “I have known Connor since he was 11 and his father Fergal asked me to show him a few things at snooker.
“Little did I know it would end up being one of the best things I ever did and I gained a friend for life, what a talent he was.
“I’ll never forget Connor running down the hill in Minnesota [Snooker Club] from school with the schoolbag that was heavier than him, he just loved snooker so much.
“In recent years my son and Connor became great friends, which I loved — two great boys together.
“Everyone at Red’s is heartbroken.
“Family is more than just blood, you will never be forgotten wee mate, we all loved you.”
Mr Kearney said the GAA club was “devastated” for Connor’s father, mother Sharon, sister Caoimhe and the wide family circle. “Connor grew up around our club, never very far away from his father, especially when he was chairperson, coach or manager,” Mr Kearney said.
“He walked in the shadow of his father and was always on first name terms with everyone associated with our club.
“He enjoyed great success as a player and team captain through the juvenile ranks of both Sean Stinsons and Casements.
“In 2015 he captained the Sean Stinson’s Óg Sport team, which competed in the All-Ireland series in Donegal.
“In 2020 he played both at U20 and reserve levels, a leg injury bringing his season to a close.
“There is little doubt that he would have risen to the ranks of a senior player for Casements in a short time.
“He was a multi-talented sportsman, enjoying particular success in snooker.”
The Northern Ireland Pool Association (NIPA) also paid tribute to Connor, saying that he “was a lovely young fella who lit up the room whenever he walked in”.
“He had a great sense of humour and touched the lives of all who knew him,” it added.
“He was a very talented pool player and represented the NIPA at both national and international level. He will be sadly missed by us all.”
Ballymena United’s Youth Academy posted: “We are shocked and saddened to learn of the sudden passing of our former player, Connor Marron, who played in our successful 2002 team and won the NIBFA cup in 2013.”
The board of governors, staff and students of St Louis Grammar School in Ballymena said they “deeply regret the death of our cherished former pupil Connor Marron”.
Sinn Féin MLA Philip McGuigian said the community of Portglenone was shocked and saddened by the “tragic death”.
“Connor was a talented sportsman with a bright future ahead of him,” he said.
“His death is such a terrible tragedy for his family and friends and I extend my sympathies and condolences to them at this sad time.”
Adam Jogee, mayor of Haringey in London, said he was very sorry to hear about the incident in the borough.
“My heart goes out to the family and friends of the person concerned as we await further details of this very sad incident,” he added.
Connor’s family has asked for donations to be made to The Kevin Bell Repatriation Trust in lieu of flowers.
The trust will be involved in bringing his remains home, with funeral arrangements to be made later.