A former public schoolboy has been punched to death during a short business trip to normally-safe Switzerland.
Popular international commodities trader Tom Lamb, 28, who attended £28,000-a-year Harrow School, was attacked during what appeared to be a mugging in Lucerne.
A single punch left him unconscious - and he was kept on a life support machine until his parents were flown to Switzerland by private jet to see doctors switch the machine off.
His parents Jeremy, 64, a retired businessman, and Jenny, 67, have spoken from their south London home of their grief at losing their youngest son.
Mrs Lamb, of Wandsworth, said: 'We are devastated. It's been an unbelievable shock.'
Mr Lamb said: 'You don't expect it in Switzerland and not in Lucerne.
'Tom was out with a friend in the city. They were walking back to their hotel when four men came up to them and while one engaged Tom's friend in conversation, one of the other guys just hit Tom.
'He went down and never regained consciousness. It would appear there was only one punch.'