Cotswold Geotechnical Holdings has become the first company to be convicted of the new offence of corporate manslaughter.
27-years-old Alex Wright, a geologist for Cotswold Geotechnical Holdings, died on 5 September 2008, when a deep trench in a development plot he was investigating in Stroud collapsed.
The Crown Prosecution Service (CPS) told the court that Wright was left working alone in the 3.5 metre-deep trench to 'finish-up' when the company director left for the day.
Two people who owned the development plot stayed at the site as they knew Wright was working alone, and 15 minutes later reported hearing a muffled noise and then a shout for help.
While one of the plot-owners called the emergency services, the other ran to the trench where he saw Wright buried up to his head. He climbed into the trench and removed some of the soil to enable him to breathe, but more earth fell and covered him, resulting in Wright dying of traumatic asphyxiation.
The prosecution's case was that Wright was working in a dangerous trench because Cotswold Geotechnical Holdings' systems had failed to take all reasonably practicable steps to protect him.
In convicting the company, the jury found that their system of work in digging trial pits was wholly and unnecessarily dangerous. The company ignored recognised industry guidance that prohibited entry into excavations more than 1.2 metres deep, requiring junior employees to enter into and work in unsupported trial pits, typically from 2 to 3.5 metres deep.
Kate Leonard, reviewing lawyer from the CPS Special Crime Division, said: "Alex Wright was a young man, full of promise. His death is a tragedy for all those who loved him and would never have happened if Cotswold Geotechnical Holdings had properly protected him."
Cotswold Geotechnical Holdings will be sentenced on Thursday 17 February 2011.