In what is sure to be cold comfort to the families of the victims, the federal government has opened an investigation whether criminal conduct led to the deaths of 29 employees in West Virginia last month. In a letter, the U.S. Attorney’s Office for the Southern District of West Virginia asked the Labor Department to temporarily halt the dozens of civil cases against Performance Coal, a subsidiary of Massey Energy Company, which owned the doomed mine. The civil cases, the U.S. District Attorney said, could interfere with the pending criminal investigation. These civil cases cite around 500 citations—300 of which are for “significant and substantial violations”—between June 2006 and the day of the explosion. Massey Chief Executive Don Blankenship is scheduled to testify before the U.S. Senate next week; the company has staunchly defended its safety record.