Just over a year ago, an explosion at the Upper Big Branch mine in West Virginia killed 29 men. The federal government called it the worst mining disaster in nearly 40 years, and amid the grief and anger there were plenty of questions, among them: Were safety rules followed? Had the government properly monitored for potential violations?
Now we have some answers. An independent panel appointed by the governor to investigate the disaster has reached a number of conclusions about who was to blame for the tragedy and whether it could have been prevented. Need to Know correspondent John Larson has those findings in this update of a story we first reported on last year.