Prosecution Corner - WorkSafe

23 May 2016

Home detention ordered after worker buried in trench collapse

A WorkSafe NZ case:

The boss of a New Zealand construction company has been sentenced to four months home detention over the death of a worker who was buried when a trench he was working in collapsed. The company was fined $56,000 and ordered to pay reparations of $121,320.

The job:

The worker was helping to install a concrete effluent transfer tank and pipes at the time of the incident.

The worker was clearing dirt in the area where the tank pit joined to the trench when the face of the trench collapsed and approximately five cubic metres of soil with an estimated weight of eight tonnes fell and buried him. Despite immediate efforts to rescue him, he died.

What went wrong:

Both the boss and the business plead guilty to the charges which included failing to take all practicable steps to ensure the safety of the worker.

The WorkSafe New Zealand investigation found that the trench had not been shored up by panels to prevent a collapse. It had been cut with vertical sides and not at a safe slope to ensure the face remained stable. In addition there had also not been any geotechnical assessment of the site to check the stability of the soil before work began.

Lessons learnt:

This accident is a reminder of the dangers surrounding excavation work and that appropriate risk/hazard management that needs to take place. It is clear that this job or any similar jobs need adequate shoring or battering work. WorkSafe New Zealand has a code of practice which includes a checklist of what you need to do before carrying out excavation work. Items include: signage, securing the area, installing drainage systems and coordinating that people and machinery work safely together. It’s best to have professional advice before carrying out any trench work if you have questions.

Things you can do:

  • Refer to the WorkSafe New Zealand – Approved Code of Practice for Safety Excavation and Shafts for Foundations.
  • Make sure you have a proper safety plan in place – for example, your site specific safety plan and task analysis.
  • Eliminate or minimise potential hazards/risks.