Massey Energy now confirms that 25 workers are dead and four more are trapped deep underground after a explosion rocked a remote West Virginia coal mine.

Mine safety officials say seven of the miners killed inside the Upper Big Branch Mine were leaving the site in a vehicle when an explosion occurred.

No word on the cause of the explosion.

The explosion destroyed all communication lines inside the mine.

Massey Energy CEO Don Blankenship told Eyewitness News, "Tonight we mourn the deaths of our members at Massey Energy,” said Don Blankenship. “I want to offer my condolences to the miners' families who lost loved ones at Upper Big Branch. And I want to thank the rescue teams and the Massey members who continue to work hard on behalf of our miners and their families."

The rescue operation has been suspended because of unsafe underground conditions. Kevin Stricklin from MSHA says the rescue will continue as soon as conditions allow.

There are reports that 48 miners were underground at the time of the explosion. Charleston Area Medical Center spokeswoman Elizabeth Pellegrin says one injured miner is in intensive care.

Initial reports say the explosion happened around 3pm Monday at Massey Energy's Performance Coal Co. Upper Big Branch Mine-South mine 30 miles south of Charleston near Whitesville. Dozens of county and state emergency personnel are on scene aiding in rescue efforts.

West Virginia Senator Jay Rockefeller released this statement Monday evening at 7:17pm. “Sharon and I are heartbroken along with the community by the tragic news unfolding of the explosion at Upper Big Branch South mine – we are sending all of our prayers and thoughts to the brave miners and their families.

“I know our dedicated first responders and local community members are doing everything they can to rescue as many people as possible and I thank them for their incredible efforts.

“I am working with state and federal officials to get as much information as possible and I am doing all I can to help make sure all resources are made available for this rescue effort.”

President Barack Obama is offering his condolences and any help needed in the aftermath of a deadly explosion at a coal mine in southern West Virginia.

Obama spoke Monday night to West Virginia Gov. Joe Manchin. The White House says in a statement that Obama offered his deepest condolences to those who lost loved ones in the disaster.

The president also told Manchin that the federal government stands ready to offer whatever assistance is needed in the rescue effort.

According to the Mine Health and Safety's website, this is the fourth fatal accident at the Upper Big Branch Mine since 1998. The mine opened in 1994.

On January, 23 1998 a utilityman was crushed when the undercast he was working on fell.

On March 29, 2001 a miner was injured when a boulder fell on him. He died two days later.

On July 19, 2003 an electrician was repairing a shuttle car cable when he was electrocuted.

This is now the worst mining disaster in West Virginia since 78 people were killed in an explosion at Mountaineer Coal Mine #9 in Farmington in November, 1968.