Ontario's Ministry of Labour is investigating a workplace accident that killed a 26-year-old man as he worked at a privately-owned quarry near Manotick.

The man was working an excavator Thursday morning at 6107 First Line Rd., a jobsite owned by Green Valley Environmental, a waste water company specializing in septic system services.

As he scooped up part of a 30-50-foot mound of rock and gravel with his machinery, it's believed part of the pile collapsed, tumbling on top of him.

The incident crushed the cab, with him inside. He was pronounced dead at the scene.

While the number of workplace accidents in Ontario is actually decreasing, the number of workplace fatalities is on the rise.

In Ontario, the number of workplace fatalities has increased about 35 per cent in the last 10 years. In 1999, there were 234 deaths on the jobsite. In 2008, that number was up to 335.

Recently, the president of a Sault Ste. Marie company was in court facing charges of criminal negligence causing death after a worker was killed.

The Centre for the Study of Living Standards says employers need to take more responsibility for the safety of their workers.

Although the Ministry of Labour is investigating Thursday's incident, no charges have been laid.

With a report from CTV Ottawa's Catherine Lathem