How safe are Chile's copper mines?
The accident at the San Jose mine, where 33 men remained trapped underground, is a reminder that digging for copper in Chile can be a dangerous business, particularly when the price of the metal is high.
Chile produces a third of all the copper in the world. The country's economic welfare is heavily dependent on exports of the metal to Europe, the US and, increasingly, India and China.
When the copper price is low, multi-national companies like BHP Billiton, Anglo American and Xstrata - along with Chile's state-owned mining giant Codelco - account for the lion's share of production, because they are big enough to ride out the depressed prices.
But when the price is high, as it has been in recent years, smaller companies enter the market too. Speculative part-time miners - some with only limited experience - head out into the Atacama Desert and the foothills of the Andes.
Mines that had long since closed because they could no longer turn a profit suddenly find that they can. They reopen, often with no better safety standards than those in place on the day they closed.
The mine at San Jose is owned by San Esteban, a medium-sized mining company which is now being sued by families of some of the miners trapped underground, who claim the company failed to make safety improvements despite three deaths at its mines over six years, and dozens of accidents.
They are also suing Sernageomin, the state regulator of mines, for allowing the company to reopen in 2008 following its closure a year earlier over a death.
"There is undoubtedly a link between the price of metal and the number of people operating in the business, particularly in the small and medium-sized mines," said Miguel Angel Duran, president of Chile's Mining Council, which represents 16 of the biggest mining companies operating in Chile.
In 2007 and 2008, at the height of the boom in copper prices, there were more deaths in Chilean mines than in any other years during the decade. In 2007, when the copper price averaged a record $3.24 per lb, 40 miners died in accidents. In 2008, when copper was at $2.88 per lb, the death toll hit 43. The average for the decade was 34.
In contrast, the safest year in the history of Chilean mining was 1999, when the average copper price fell to just 72 cents, its lowest level in over 10 years, a consequence of the Asian crisis.
For the industry's smaller players, whose safety standards tend to be the poorest, there was simply no incentive to mine copper.
"It shouldn't be the case that when the price rises, the number of accidents rises too," said Andy King, national co-ordinator for health and safety at the massive North American trade union, United Steelworkers.
"In fact, the opposite should be the case," said Mr King, who visited the San Jose mine last month and has been deeply critical of safety standards at Chilean mines. "The higher the price of the metal, the safer the mine should be, because the company has more funds to improve safety."
Despite the fluctuations in both the price of copper and the number of accidents, the long-term trend is positive. There are far fewer serious accidents at Chilean mines than in the past.
The National Geology and Mining Service (Sernageomin), the state body tasked with regulating the industry, says there was an average of 0.41 deaths in Chilean mines for every one million hours worked during the 1980s. By the 1990s that figure had dropped to 0.28 and by the past decade to 0.13.
Figures from Chile's Department of Social Security suggest that mining is among the safest industries in the country.
Last year, there were 2.2 accidents in Chile's mines for every 100 workers, compared to 5.7 in the construction industry and 7.2 in agriculture and fishing. That is largely because mining is dominated by foreign companies with stringent internal safety procedures.
In the wake of the San Jose accident, the government has said it will more than double the number of mine inspectors in Chile, ensuring that on average, the country's mines are inspected every eight months. Until now, there were just 18 inspectors at Sernageomin charged with overseeing an industry which employs 175,000 people.
In addition, President Sebastian Pinera has established a commission to look into safety standards at Chilean workplaces across the economy. The commission has 90 days to come up with proposals to make Chile a safer place in which to work. It is due to report its findings on 22 November.
Whatever the commission proposes, mining in Chile will remain a risky business. In the first eight months of this year, 31 Chilean miners died in accidents caused by cave-ins, electrocution, explosions, asphyxiation and falls from heights.
If all goes to plan in the next few days and weeks, the names of the 33 men trapped at the San Jose mine will not be added to that lamentable death toll.