Coal has long been a key source of energy and a major source of income for millions of Americans. But coal production in the U.S. is now at its lowest level in 30 years. Several big coal companies have closed recently and the Obama administration has stopped issuing new coal mining leases on public lands. The change has affected the lives of tens of thousands of people in the coal mining region in the Appalachian Mountains. Nadeem Yaqub reports.