Massey Energy CEO Don Blankenship took questions from a selected group of reporters for more than two hours at the company's West Virginia offices Friday. Howard Berkes/NPR hide caption

itoggle caption Howard Berkes/NPR

Methane monitors are mounted on 30-foot-long continuous miners like this one because methane gas collects in pockets near the roofs of mines. File photo hide caption

itoggle caption File photo

President Barack Obama reviews a map of the Upper Big Branch mine 10 days after the deadly explosion that killed 29 mine workers. Also pictured are MSHA coal mine safety chief Kevin Stricklin (at left), Assistant Secretary of Labor Joe Main (second from left) and Labor Secretary Hilda Solis (far right).  Immediately after this meeting, the President promised "to ensure that we're pursuing mine safety as relentlessly as we responsibly can." Pete Souza/The White House hide caption

itoggle caption Pete Souza/The White House