Xian Hou Ye, aged 56, was crushed and suffocated by nine tonnes of soil in the incident at Waldram Park Road, Lewisham, on 30 September 2010.
Woolwich Crown Court heard on Friday (11 October) that he was one of a group of workers contracted by Croxley Green-based HMB Services Ltd and company director Vijay Patel to convert a three-storey property into nine flats.
The property was co-owned by brothers Mukesh Shah and Kiran Shah, also from Hertfordshire, who appointed HMB Services and Mr Patel as the principal contractor to oversee the project.
As part of the works, a 7m-long trench had been dug, 1m-2m wide and almost 3m deep. This was being extended at one end at a 90-degree angle to form an L-shape.
A hydraulic excavator was digging the extension while Mr Ye was working in the deeper existing section. As work progressed, the inside corner of the L-shape caved in and buried him under nine tonnes of earth. He died at the scene despite frantic efforts to dig him out.
The subsequent Health & Safety Executive (HSE) investigation found that the trench had been inadequately supported with sheets of plywood and timber props.
Mukesh Shah and Kiran Shah, both of the Optima Business Park, Pindar Road, Hoddesdon, Herts, were each found guilty of two separate breaches of the Construction (Design and Management) Regulations 2007. Mukesh Shah was fined £40,000 with costs of £34,750. Kiran Shah was fined £25,000 and was also ordered to pay £34,750 in costs.
The brothers were told they would be jailed if they failed to make the necessary payments.
Vijay Patel, of Valley Walk, Croxley Green, Herts, was given 270 hours of community service after pleading guilty to a single CDM Regulations breach. The court ruled he had no means to pay a fine or contribute towards costs. HMB Services Ltd, of the same address, is now dissolved so the company avoided prosecution.
After sentencing HSE principal inspector Russell Adfield said: "Mukesh and Kiran Shah were having this conversion undertaken as part of a business venture and they were therefore ‘clients’ in this project. A client has a very major influence over how a construction project is run as they have responsibility for appointing competent advisors – principal contractors – and ensuring that arrangements are in place for carrying out the project safely.
"The clients in this case failed on all fronts. They had no advisors to help them understand what was required of them, the principal contractor they appointed was not competent to manage this work safely and there were no formal arrangements in place to ensure the safety of those workers on site.
"It appeared neither the clients nor principal contractor had any understanding of the very real risks on that site – or how to ensure those risks were controlled."