FRONTLINE investigates the rise of severe black lung disease among coal miners, and the failure to respond. An investigation with NPR reveals the biggest disease clusters ever documented, and how industry and government failed to protect miners.

Also this hour, a report from Yemen. Correspondent Safa Al Ahmad reports from inside Yemen, investigating the escalation of the U.S. fight against Al Qaeda and its impact on civilians. She goes to the front lines, visiting the sites of Special Forces raids and a deadly drone strike to shed light on how the U.S. counterterrorism strategy is playing out on the ground.