The Mine Safety and Health Administration (MSHA) has launched an investigation into the West Virginia coal-mine accident that left 12 miners dead.

Thirteen miners had become trapped at Sago Mine in West Virginia after an explosion Monday. Only one of the 13 miners survived the incident, contrary to early reports that 12 of the 13 had survived. In addition to investigating the accident, MSHA says it will investigate how emergency information was relayed about the trapped miners' conditions.

"Now that the rescue and recovery phases of this operation are nearing completion, the Mine Safety and Health Administration will begin an in-depth investigation of the accident," says David Dye, acting head of the agency. "This starts with the appointment of a separate MSHA investigative team that will evaluate all aspects of the accident and response. As always, the purpose of MSHA's investigation will be to improve mine health and safety and prevent such tragedies in the future."