A grieving father has spoken of his "unbearable" agony after his teenage son and two close friends were killed in a bus crash on their gap year in Thailand.
Bruno Melling-Firth, Conrad Quashie and Max Boomgaarden-Cook were on a coach bound for the northern town of Chiang Mai when it collided head on with another bus in the early hours of Tuesday morning.
Gerhard Boomgaarden, 48, father of Max, said the boys were just days into their first "big trip" together when they were killed in Khlong Khlung, in the Kamphaeng Phet Province. A fourth boy, named only as Jack, had been travelling with the group but escaped the accident with minor injuries and has returned to Britain.
"I didn't know that a body could physically produce so many tears," Mr Boomgaarden said. "I didn't know that it could hurt so much and so persistently."
Mr Boomgaarden, who works in publishing, said he, Max's stepmother Madeleine, his brother Leo, 16, half-brother Ivan, six, and 13-year-old Leon Flint, who lives with the family, are "holding together". But he added: "The last three days have been absolutely unbearable. You can't sleep, you pace up and down, you can't think."
Max, a volunteer for a leukaemia charity, attended The Charter School in Dulwich and was due to go on to Manchester University to study history and politics.
"He was very bright and adventurous," Mr Boomgaarden, from Herne Hill in south-east London said. "He was very articulate and had loads of energy. He was always up to something."
The teenager had flown to Thailand last Thursday with his three friends, all former pupils at The Charter School, for their nine-week trip. The students, all 19 and from south London, had been planning to visit Thailand's northern hill tribal areas, famous for remote treks and popular among travellers.
Mr Boomgaarden said Jack, who flew home following the crash, was suffering from "survivor's guilt" as the only member of the group to escape with his life.
The Foreign Office said one further Briton injured in the "serious accident" is recovering in a Bangkok hospital.