Rescue operation underway following deadliest mine explosion since 1984

Twenty-five coal miners were killed and four were still missing underground following an explosion in a West Virginia mine in the deadliest mine explosion in decades, reported Reuters.

The accident happened at the Upper Big Branch Mine in Montcoal, owned by Massey Energy, about 30 miles south of the state capital of Charleston.

The blast occurred in the mid-afternoon on Monday (April 6). Kevin Stricklin of the US Mine Safety and Health Administration told reporters four men were still missing and the rescue operation was underway.

Rescuers were hampered by methane gas and smoke underground, which were raising the chances of a second explosion.

The death toll of 25 makes it the deadliest U.S. mining disaster since 1984 when 27 miners died in a fire in Utah, according to the United States Mine Rescue Association.