North Dakota has been a key player the U.S. shale boom, along with states like Texas and Oklahoma. But alongside the immense economic benefits that the state reaps, there is a heavy price to pay. According to a new report released by the American Federation of Labor and Congress of Industrial Organizations (AFL-CIO), North Dakota has the highest worker fatality rate in the country, with 17.7 deaths per 100,000 workers in 2012.

This is not a one-off event for North Dakota. The state led the way in the grim statistics in 2011 as well, when it recorded 12.4 fatalities per 100,000 workers. The rapid growth of the oil and gas industry has contributed to the increase, as fatality rates stood at seven per 100,000 in 2007, prior to the energy industry revolution. Still, the increase between 2011 and 2012 is dramatic and raises questions regarding employees' safety in North Dakota, the Associated Press reported.

The full report by the largest U.S. labor federation is due to be released next week. It also lists other states with fatality rates higher than the national average, including Wyoming, Alaska, West Virginia and South Dakota. In 2011 the national worker fatality rate stood at 3.5 deaths per 100,000 employees.