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...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 correlation between the copper price and the accident rate at Chilean mines is clear...[T]he 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...For the industry's smaller players, whose safety standards tend to be the poorest, there was simply no incentive to mine copper. [also refers to San Esteban]