Monday’s explosion that killed 25 miners at Upper Big Branch Mine in West Virginia came at a mine that had been flagged by inspectors for a series of violations – 3000 since 1995 and more than 500 in 2009 alone.

How does that compare to other mines? Because of the way the federal government releases the data, we can't say.

Data on safety inspections is published in the Department of Labor’s Mine Safety and Health Administration (MSHA) Web site, where users can find information on mine safety, inspections and violations. But getting to it is the hard part ...