A 44-year-old groundworker was not wearing his seat belt when his dumper truck overturned and he was crushed to death, an inquest heard.

Royston Dean, of Perrin Close, Banbury, was working with his brother Stephen at a new waste water management site in Frampton-on-Severn, Gloucestershire, when the accident happened in November 26, 2008.

They were using the dumper and a mechanical digger, the Gloucester inquest was told.

The pair were filling the space around the outside of a tank with clay to form a barrier in case any fluid should escape.

Mr Dean was pronounced dead at the scene.

The jury at the inquest held in the North Warehouse, Gloucester, on Tuesday returned a verdict of accidental death.

Mr Dean’s brother Stephen Dean told Gloucester coroner Alan Crickmore they were both self-employed groundworkers who had been working at the site since November 21.

He said: “We had done maybe 30 loads during the day and had almost finished.

“At about 3.15pm I used the digger to fill the dumper with clay and Roy drove it up the ramp to dump next to the tank.

“After a few minutes, when he did not return, I looked across and saw the wheels of the dumper in the air.

“I ran over to it and could see Roy trapped under the roll cage and his face was covered with blood. He was partly covered with mud and completely unconscious.

“I could not get a pulse and shouted to the site manager Peter Dyer to get an ambulance. I tried to clear his airways of blood and when the paramedic arrived he took over, but he could not get any response either and pronounced him dead.”

Mr Dyer told the inquest he was fully aware of health and safety requirements and both the Dean brothers had been inducted when they arrived on the site.

He said he was happy that Steve and Royston were competent and happy with the standard of their work.

The inquest was told that the cause of death was a large skull fracture together with severe injuries to the chest.

Health and safety inspector Peter Chilcott said the tyre pressures of the dumper were very low. He added: “I think the driver could have tried to shake the sticky clay out of the bucket and the dumper fell forward and rolled over.

“The site manager had asked Royston Dean to wear his seatbelt earlier in the day, but it was not fastened when the incident happened.

“If it had been, he may still have been injured, but he would not have been trapped by the roll cage.”