Black lung threat increasing among coal miners

Coal mining has always been a dangerous job, with one in every five miners ending up with “black lung” disease. But today, in Appalachia, miners are suffering from black lung at increasingly younger ages. “Sunday Morning” senior contributor Ted Koppel talks with miners and union officials who say coal companies routinely break the rules that could help protect their employees’ health; and looks at a new government proposal that might offer real protection for miners, but which is facing opposition from some in Congress.