According to official statistics released by the federal Mine Safety and Health Administration (MSHA), 2012 was the second consecutive year in which fatalities occurring during mining operations reached an all-time low.

Joseph Main, assistant secretary of labor for mine safety and health, said that 36 miners were killed in work-related accidents in 2012, including 19 in coal mines and 17 in metal and non-metal mines. The total number of fatalities was one more than the all-time best year, 2009, but with an improving economy driving more mining than in 2009, the fatality rate declined to its lowest level ever. Looking at specific states, the biggest proportion of deaths (seven) took place in West Virginia, with five in Kentucky, three in New York and Alabama, two in Montana and Florida, and one in Arizona, California, Colorado, Georgia, Illinois, Indiana, Maryland, Nebraska, Nevada, North Carolina, Ohio, Oklahoma, Tennessee and Virginia.

Calculations of fatality rates are based on the number of mining deaths per 200,000 hours worked, the MSHA said in a statement. Last year 10 miners died as a result of powered haulage, which was the most common cause of fatality. Machinery accidents killed six more workers, the same number as slips or falls, while rib falls killed three miners. The biggest cause for concern last year was the death of nine supervisors, or 25 percent of the total — a proportion that significantly exceeds those recorded in previous years.

RELATED: US mining industry hopeful for 2013

In terms of experience, the most fatalities occurred among miners with less than one year of experience either at the particular mine, or at doing the particular task they were performing at the time of the accident. This fact highlights the importance of appropriate training and the need for more effective task training before miners are asked to complete a given task, commented Main.

While mining fatalities are decreasing thanks to the implementation of and compliance with tougher regulation, the deaths that happened last year were all preventable, Main said. That is why more work should be done to ensure workers are protected and all injuries, illnesses and deaths are prevented, he added.

Among the most common causes of work-related injuries and fatalities are pinning, crushing and striking in underground coal mines. Historically, these have accounted for a high number of deaths. Statistics show that between 1984 and 2012, 73 workers died from one of these types of accidents. Nearly half of them were associated with continuous mining machines and could have been prevented by a number of precautions, such as using proximity detection, a system that prevents mining machinery from coming into contact with miners. According to MSHA estimates, a proximity detection system could have prevented several non-fatal injuries. The administration stated that last year three deaths at coal mines could have been prevented if such systems had been put in place. As a means to improve protection, a number of U.S. mine operators have already invested in such systems, the MSHA noted.