The heartbroken parents of a Hutton toddler who died in hospital have been told: 'You will never know what killed her'.

Hayley Debond was just 23-month-old when she suffered a fit and was rushed to intensive care.

Despite efforts from doctors, the toddler died within a day from the mystery illness and an inquest has heard the cause will probably never be known.

Experts were unable to rule out the brain bug meningitis, and said the youngster had contracted a rare form of flu seven months earlier.

But they could not diagnose either condition as the cause of Hayley's fit.

The inquest heard Hayley was too old to have been the victim of cot death. So her devastated parents were told their child's death will remain a mystery.

Dad Gary, of Rayleigh Road, said: "One night she was happy and playing with me, and the next she was dead. It was just an unlucky thing that happened to her."

Westminster Coroner's Court heard how Hayley fell ill at the family home in the early hours of February 18 this year. The following day, as mum Sharon was preparing Hayley for a doctor's appointment, the child had a sudden fit.

An ambulance was called, and Hayley was rushed to Oldchurch Hospital in Romford.

She was transferred to a children's intensive care unit at St Mary's Hospital in Paddington, London, but died at 4pm on February 19.

Dr Alan Ramsay, child pathologist at Great Ormond Street Hospital, told the court that Hayley had suffered no injuries, and there were no signs of anything suspicious.

Hayley had contracted a form of flu, called influenza A, but there were no definite answers as to the cause of her death.

Recording an open verdict, Dr Knapman said: "The influenza A virus was found, but we don't know whether that's significant. Even after looking at all aspects of it, Dr Ramsay cannot find any process to explain why this child collapsed and died.

"The possible, and most likely, explanation is that there was some sort of infection that cannot be diagnosed by present-day methods.

"I want to make it perfectly clear that there is no suspicion of ill-treatment, and from the evidence I heard, the parents acted perfectly reasonably and did what any normal parent would have done."

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