Richmond, Virginia, US-based coal producer Massey Energy Company on June 2 announced that two teams entered the Upper Big Branch Mine on the morning of the same day at approximately 10 am local time. The company, the Mine Safety and Health Administration (MHSA) and the West Virginia Office of Miners Health Safety and Training were among the teams that entered the mine.
The company said that the teams were withdrawn after air quality samples indicated the presence of adverse air conditions, adding that they were analyzed further and it was determined that the teams could safely reenter the mine again. "The teams are continuing their examination of mine conditions at this time. We continue to call for a fair and independent investigative process." Massey added.
The Upper Big Branch Mine disaster killed 29 coal miners in April.