CHARLESTON, W.Va. -- Twenty-one U.S. coal miners died on the job in 2011, the second lowest number in more than a century of record-keeping, the federal Mine Safety and Health Administration said Thursday. The lowest number was 18 in 2009.Kentucky led the nation with eight coal-mining deaths, followed by West Virginia with six, according to MSHA.Two coal miners died in Ohio. Arizona, Colorado, New Mexico, Virginia and Wyoming each recorded one coal-mining fatality, MSHA said. Several of the larger coal-producing states, including Alabama, Pennsylvania, Illinois and Utah, experienced zero mine fatalities last year, MSHA noted.MSHA chief Joe Main, in his agency's annual statement of mining fatalities, said even one death in the industry is too many."Mining deaths are preventable," Main said. "While fewer miners are dying on the job, we can never alter our focus because, as we know, things can change in a moment."In addition to the 21 coal-mining deaths, 16 miners died at metal- and non-metal mining operations, MSHA said. The total of 37 deaths across all mining sectors compares to 48 in 2010, a year that included 29 deaths in the Upper Big Branch Mine Disaster.Of the 37 deaths, 12 occurred at surface coal mines, 11 at surface metal/non-metal mines, nine at underground coal mines and five at underground metal/non-metal mines."The year that the Federal Mine Safety and Health Act of 1977 passed, 273 miners died and, since that time, fatality numbers have steadily declined," Main said. "In order to prevent mine deaths, operators must have in place effective safety and health management programs that are constantly evaluated, find-and-fix programs to identify and eliminate mine hazards, and training for all mining personnel."Reach Ken Ward Jr. at firstname.lastname@example.org or 304-348-1702.