The FBI has told relatives of 29 miners killed last year in an explosion at the Upper Big Branch coal mine in West Virginia the miners may be crime victims. The Charleston Gazette obtained a copy last week of a letter sent from the bureau\'s Charleston office, the Pittsburgh Post-Gazette reported Monday. The letter was signed by the agent supervising the office, Joseph I. Ciccarelli, and was dated March 28. The explosion occurred April 5, 2010 at the Upper Big Branch mine, owned by Massey Energy. The letter said the FBI is involved in the investigation of potential violations of federal laws. \"In connection therewith, you may be a victim of a federal crime,\" the letter said. \"We appreciate your assistance and cooperation while we are investigating this matter. We would like to make you aware of the victim services that may be available to you and to answer any questions you may have regarding the criminal justice process throughout the investigation.\"