A company behind a theme park where a schoolgirl plunged to her death from a white knuckle ride will be sentenced today for a fatal health and safety breach.

Sunday school teacher Hayley Williams, 16, fell 100ft from the top of the spectacular Hydro ride as it began an almost vertical descent into a plunge pool.

It happened at the popular Oakwood Theme Park, near Narberth in April 2004 as horrified visitors looked on.

The schoolgirl, from Pontypool, was visiting the attraction with family and friends at the time.

A sentencing hearing, which could last up to two days, begins at Swansea Crown Court today.

The Health and Safety Executive served a summons on Oakwood Leisure Ltd in February at the end of its investigation into the fatal accident.

The firm was charged with a single offence of failing to ensure persons not in its employ were not exposed to risks to their health and safety.

The charge also named Swansea schoolboy Martin Rothwell, who was on the ride at the time and suffered a minor head injury after being hit by the falling teenager.

Company bosses initially pleaded not guilty to the charge at a first hearing at Haverfordwest Magistrates' Court, back in May.

But two months later at the same court the company's legal team said it now admitted the single charge.

Two-and-a-half-years ago the same court had been the venue for a four-day jury inquest in to the fatal accident.

At its conclusion, the jury recorded a narrative verdict in to the death.

Parents Alan and Beverley Williams afterwards spoke of their bitter disappointment that the coroner had ruled out unlawful killing as a verdict.

The hearing today takes place five months after the company admitted the single charge which potentially carries an unlimited fine.