A coroner has ruled that a girl died accidentally when she fell from a bridge on to a train during a late-night barefoot run.
Private school pupil Zoe Miller, 13, was said to be in the habit of taking exercise to help her sleep.
An inquest heard she enjoyed skipping and running to burn off energy, and on the night in question had clambered on to the parapet of a bridge to cross over railway tracks.
When a 60mph train passed underneath in the dark she is thought to have become 'disorientated' and fallen on to it.
Her body was spotted the next morning by another train driver as he passed through Berkhamsted, Hertfordshire.
Zoe's parents, who live 100 yards away, had already realised that their daughter was missing and police contacted them shortly afterwards with the devastating news.
Deputy coroner Graham Danbury heard that Zoe had spent much of her life in South Africa, Nigeria and Zambia where she regularly went out walking or running barefoot to help her sleep.
She returned to the UK last summer with her mother Jane, 46, a senior health adviser for the Department for International Development, father Rob, 48, a scientist specialising in storing biological data, and sister Sam, 11.
Her parents released a statement after the inquest in which they said they 'miss her desperately'.