Underlining the close ties between many of the miners, he drew attention to a particular family (not identified by name) where one member, who had worked the day shift, lost his son, his older brother, and sister's son when the explosion occurred.
The force of the blast was so severe, Manchin said that the rail which "most of your equipment and shuttles and man trips run off [...] look[ed] like a pretzel" after the explosion.
"One of the miners that is missing was on the long wall, three were working in a mine section together," he told reporters.
He said that he expects more information to be released later today, but counselled well-wishers against coming to the site of the explosion, "if they want to help they should help through the local Red Cross and pray."
"In West Virginia our clergy is our grief counselors; I don't know how to explain it, the people were just so solid and they're coming together."
The blast could be heard, and felt, for miles.
"Before you knew it, it was just like your ears stopped up, you couldn't hear," miner Steve Smith told ABC Radio. Smith felt the blast while working underground at another site about 7 miles away.
"The next thing you know, you're just right in the middle of a tornado," Smith said. "We were able to make it since we weren't that far underground right there at that side of the mountain.
"We just hurried up and high-tailed it back to the outside," he said.
At least one of the injured miners was taken by helicopter to the Charleston Area Medical Center where a triage area has been prepped since the announcement of the explosion, a hospital spokesperson told ABC News.
One of the injured miners passed away on the way to the hospital, the governor said. A further two are still in hospital, with one in intensive care, according to Charleston Area Medical Center spokeswoman Elizabeth Pellegrin.
Don Blankenship, chairman and CEO of Massey Energy, confirmed the reported dead and missing "with a heavy heart."
"Our top priority is the safety of our miners and the well-being of their families," Blankenship said in a statement. "We are working diligently on rescue efforts..."
President Obama contacted Gov. Manchin and "promised to make every asset available," the governor's office said.
Sen. Jay Rockefeller, D-W.Va., said he was "heartbroken" by the news and offered condolences and words of hope to the families of the miners involved.
"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," Rockefeller said in a statement.
He told CNN that responders from at least three counties were involved in the rescue operation.
"Mine rescue operations in West Virginia are incredibly aggressive. They have to fight their way through the fog… sometimes its hard for them to get to the mine.. it's a horrible, horrible process," he told CNN.
The risk of methane gas build-up inside mines has led federal and state regulators to demand that mine operators store extra oxygen supplies inside mines. In addition to airtight containers stocked with oxygen, all miners at the Upper Big Branch also carry an oxygen container on their belts.