upper big branch mine in southern west virginia. six miners are confirmed dead. 21 are missing. many of those are believed to be trapped under ground. the mine is located 30 miles south of charleston. this is a large mine producing more than a million tons of coal each year. it is staffed by about 200 employees and reportedly has an air-tight refuge chamber stocked with emergency air supplies. they're designed to provide enough breathable air for four days. it is also equipped with wireless communications and underground tracking systems. at least three fatal accidents have occurred at this mine over the last dozen years. nationwide the level of mine fatalities has fallen to its lowest level in more than a century. we'll continue to monitor this developing situation. stay tuned for live updates during our primetime hours beginning with "countdown" at 8:00 p.m. eastern here on msnbc. now back to "hardball."