The security chief of a Massey Energy Co. subsidiary was charged in a federal indictment with obstructing the investigation of a 2010 explosion that killed 29 miners at the company’s Upper Big Branch Mine in Montcoal, West Virginia, federal prosecutors said. The indictment accuses the security chief of lying to an FBI agent and a federal Mine Safety and Health Administration (MSHA) inspector. It also charges he ordered an employee to dispose of thousands of pages of security documents from the Raleigh County mine more than 9 months after the explosion. The indictment said Massey regularly violated federal law by warning underground workers when government officials arrived to conduct safety inspections at its mines. The father of one of the victims told a congressional panel last May that Massey used radio messages warning that a man was on the property when MSHA arrived for an inspection. The security chief is accused of lying when he told FBI and MSHA investigators January 21 that company policy prohibited such warnings.