Eleven workers have been killed in industrial accidents in New Zealand in less than two months since the beginning of this year.

Last week, three workers perished when they were overcome by toxic fumes while flushing out sewerage lines underneath Auckland's central business district. Several firefighters who came to rescue the men were taken to hospital suffering from the effects of gas inhalation. The tragedy was the country's worst industrial accident in 20 years.

The three men, Eddie Rihia, 30, Kenneth Karu, 47, and Darren Skeen, 19, were employed by two firms contracted by the city-owned water company, Metro Water. They were working down a manhole without basic gas detection equipment, and were apparently unaware of a lethal cocktail of hydrogen sulphide, carbon dioxide and low levels of oxygen. They were discovered unconscious and could not be revived by rescuers once they were brought to the surface.

Spokesmen for the companies and Metro Water were quick to distance themselves from any responsibility for the workers' deaths, and to turn the blame onto the men themselves. Simon Ericson said on behalf of the contractors, Aquatech, that the company was "at a loss to understand" how the accident had happened, as the procedure being used was "never to involve men being below ground level". He claimed that the men had ignored "very strict guidelines and procedures". Ericson did not, of course, consider why the men would have ignored the guidelines, if it were indeed the case.

The deaths are part of a wider picture of deteriorating workplace health and safety produced by continual restructuring and cost-cutting. Many industries are now run almost entirely on sub-contracting arrangements where responsibility for workers' safety is removed from the hands of a central employer and given over to small contractors who only remain in business to the extent that they can compete by cutting costs and speeding up work.

As a result, workplace fatalities are increasing each year. There were 42 deaths in 1996, and 46 in the year 1997-8. Over the last six months there have been 28 deaths, a rate of more than one every week. The forestry and construction industries have a particularly gruesome record, with 11 workers killed in construction since last July.

In a report issued last week, Hazel Armstrong, a health and safety officer for the Engineers Union, said workers are dying while employers are getting away with unsafe work practices. Armstrong's report was based on an analysis of the activities of the Labour Department's Occupational Safety and Health (OSH) Division, which has overall responsibility for the monitoring and enforcement of occupational health and safety laws.

Her report shows that of the 42 workplace fatalities in 1996, only six employers were prosecuted by OSH. Armstrong cites at least 13 other cases where there was clear evidence of employer culpability that should have led to a prosecution. In some cases, employers have escaped the attentions of OSH despite repeated fatalities. Three railway workers have died in separate accidents over the last year, but Tranzrail has not been called to account over any of them.

OSH itself has been downsized. The inspectorate was reduced some years ago, and is not adequately manned and resourced to inspect the country's worksites. Most employers know they can go for years without ever seeing a factory inspector. According to Armstrong's report, lack of resources and skill within the department is one of the chief causes of the failure to prosecute employers.

The health and safety legislation only provides minimal protections for workers. Not only do employers count on avoiding prosecutions when their employees are killed, but serious injuries result in token fines. This week a Wellington engineering company was fined a paltry $13,000 after the district court found it guilty of failing to ensure the safety of a worker who sustained horrendous multiple injuries when he fell 23 floors down a lift shaft.

Stuart Jones, a 23 year-old welder slipped, through a gap between the roof and an inadequately secured hoist, from which he was working at the top of the lift shaft. His survival was described as "miraculous good fortune" by the judge. He had bounced off the shaft on the way down, and his fall was softened by a pile of plywood at the bottom.

Jones suffered a fractured left hip, knee, tibia and fibula and ankle, a broken left rib, dislocated right ankle, twisted right wrist and a broken bone in one foot. He was hospitalised for more than six weeks, required seven operations, and nine months later still needs to use crutches.

The company had been contracted to complete the lift shaft, a major construction, within a 14-day deadline. It was working two crews of three men in 12-hour shifts. Modifications had been made to the hoist to enable the work to be carried out more quickly from the roof.

Under New Zealand's accident compensation laws, workers do not have the right to sue employers over injuries sustained at work. Workers and employers pay levies into an accident compensation scheme, which is meant to cover workers for injury and loss of earnings. In Jones' case, the only compensation payment he will receive, apart from his medical costs and lost wages, is half the company's $13,000 fine, issued on the direction of the court.

The National Party government is currently preparing to reduce the accident compensation scheme further by removing the monopoly held by the state-owned insurer, the Accident Compensation Corporation. This will make it possible for employers to take out insurance cover with the cheapest private insurer they can find, while opening up work insurance as a source of profits.

It is also necessary to consider the role of the trade unions in the rising toll of serious and fatal injuries. In a national radio interview during the week, Ashley Russ, secretary of the Building Trades Union, said the de-unionisation of the construction industry following the introduction of the Employment Contracts Act had removed a vital layer of union delegates from supervising the safety of workers on jobsites.

But the lack of safety delegates is only a symptom of deeper causes. Firstly, the Employment Contracts Act was only passed into law with the conscious cooperation of the Council of Trade Unions, of which both the Building Trades Union and the Engineers Union were, and remain, influential affiliates. Secondly, the failure of the trade unions to oppose the Employment Contracts Act was itself a product of their collaboration with big business in the drive for profits and productivity throughout the 1980s.

The unions have become notorious for cooperating with employers in establishing the very industrial conditions that are the cause of increasing rates of deaths and accidents. In the engineering industry, the union has enforced every demand employers have made for cutting jobs and speeding up production, while its delegates are trained, not to defend the interests of workers, but to act as management agents.