The U.S. Labor Department has opened an investigation into the deadly coal mine accident in West Virginia that killed 12 workers.

In a statement released Wednesday, the department said the Mine Safety and Health Administration would appoint an investigative team to evaluate all aspects of the accident and emergency response. It said the probe would also look at how information was relayed about the condition of the trapped miners.

Initial reports that 12 of the 13 miners had been found alive quickly spread through the small coal mining community. The scene turned chaotic, however, when company officials told family and friends of the victims that only one of the miners had survived the deadly mine blast.

The explosion early Monday was the worst U.S. mining disaster since 2001, when an explosion in Alabama killed 13 people.