THE cause of the horrific A127 crash which led to the death of a mother and her young daughter, will remain a mystery, an inquest heard.

Michelle Williams, 38, was killed instantly when her car hit a lorry parked in a layby last July. Her three-year-old daughter, Ruby, died eight days later at Great Ormond Street Hospital, London.

Coroner Caroline Beasley-Murray recorded verdicts of accidental death in both cases.

The mother-of-four, who grew up in Wickford, was driving back to Wales after visiting relatives in Essex when her Renault Megane hit the lorry.

The inquest was told the crash happened at about 4.30am on July 1, not long after Mrs Williams had left Wickford on the 300-mile drive to Tyn-y-Gongl, in Gwynedd, North Wales.

She reached the A128 Brentwood Halfway House turning when her car drifted towards the curb, hit it and mounted the footpath, the coroner was told.

The car returned to the A127, but its rear nearside tyre was punctured, making it hard to steer.

Road traffic investigator PC Steven Perrett said Mrs Williams appeared to have tried to control the car, but oversteered and it crashed into back of the parked Scania lorry.

He said: “Once a vehicle has started to go out of control like this, very few drivers would be able to regain control.

“A number of factors could be considered as to why she allowed the car to strike the curb, such as fatigue, or distraction, but I can’t say why.”

A post-mortem examination revealed she died of multiple injuries, but a toxicology report found no traces of alcohol or drugs in her body. Little Ruby was rushed to Basildon Hospital and transferred to Great Ormond Street, but never recovered, dying on July 9.

A doctor’s report from Great Ormond Street Hospital said she died of a severe, traumatic brain injury.

The lorry driver, who was asleep in his cab at the time of the accident, was not hurt.

Ted Skeat, Mrs Williams’ stepfather, was at the inquest with several members of the family, including her husband, Paul.

Mr Skeat told the coroner she had stayed in Wickford with them for several days before heading back to Wales.

Mrs Williams had lived in Wales for about 20 years. She was mother to sons, James and Peter from a previous marriage, and also had a son, Max and Ruby with second husband, Paul.