“Pennsylvania’s underground mining operations have gone an unprecedented five years without a fatality,” Department of Environmental Protection secretary Christopher Abruzzo said.

Another DEP official, John Stefanko, attributed the result to the mining industry’s skilled workforce, improved industry practices and departmental oversight.

Coal mine operators are required by law to report all accidents, or unanticipated events, to DEP’s Bureau of Coal Mine Safety within 15 minutes of occurrence, as this information provided insight on what could be done to prevent similar accidents.

The last underground mining-related fatality occurred in the bituminous region 63 months ago on June 23, 2009. It has been 75 months in the anthracite region and 73 months in the industrial minerals region since the last underground fatality.

Nationwide, there were 14 work-related fatalities in underground coal mines in 2013 and there have been seven fatalities to date in 2014, according to the federal Mine Safety and Health Administration.

Pennsylvania is the nation’s fourth-largest coal-producing state. In 2013, it produced more than 67.1 million tons of coal, 46.7Mt of which came from underground mines. The underground mining industry employs more than 5600 Pennsylvanians.