Stuart Cunningham-Jones was sitting on the top deck of the bus

Stuart Cunningham-Jones died and 30 children were injured when the double-decker careered off the road near the village of Ystradowen in the Vale of Glamorgan in December 2002.

One 14-year-old pupil - who cannot be identified for legal reasons - told the hearing in Cardiff on Tuesday - how he was standing near the baggage rack of the bus when he saw another pupil "mess about".

The inquest jury heard that the driver was distracted up to 10 times prior to the crash - which included one child attempting to play around with the indicators and reaching over to sound the horn "just for a laugh".

"I was getting ready to get off the bus when the boy pushed the horn," the teenager said.

"I don't know how the bus crashed, the driver reacted, he moved the steering wheel or the boy did, and the bus crashed. I don't know."

The court was told that a male pupil had distracted the driver six or seven times.

The bus was carrying 72 children when it crashed

The driver had warned him to stop but, the jury was told, the child continued trying a further three times to interfere with the controls.

The inquest later heard from motorist Gary Price, who was travelling in the opposite direction shortly before the crash.

Mr Price, whose daughter was on the bus, said he saw a boy in the front standing directly behind the driver.

He told the jury that the boy "seemed to be reaching across the driver".

"I thought that if he carries on like that there's going to be an accident," he said.

Before witnesses began giving evidence, Coroner for Cardiff and the Vale of Glamorgan, Lawrence Addicott, told the jury of seven men and three women, that no one was "on trial" and there were no sides.

Stuart's parents, Joanna and David Cunningham-Jones, who have become campaigners for better bus safety for school children, have been calling for an inquest into his death to be carried out for some time.

The Crown Prosecution Service has already said that no one will face criminal charges over the death.

No mechanical fault

Stuart, a pupil at Cowbridge Comprehensive School, was sitting on the top deck of the service bus when it left the road.

The vehicle fell into a field and came to rest on its side after hitting a tree.

A police investigation got under way but tests later showed that there were no mechanical faults with the bus which was carrying 72 children.

Current legislation allows three children under the age of 14 to sit on a bus seat designed for two adults.

After Stuart's death friends of the family formed a campaign group calling for the-so called 'three for two' law to be scrapped and for seatbelts to be installed on all school transport.