Report on the coal mine explosion in Montcoal, W. Va. finds Massey Energy Co to blame as a result of safety failings. (Jeff Gentner/Associated Press)

An independent investigation concludes the West Virginia coal mine explosion that killed 29 men last year was the result of safety failings by owner Massey Energy Co. and rejects the company's argument that a sudden gas buildup caused the deadliest U.S. coalfield disaster since 1970.

The report released Thursday and commissioned by the state's former governor said Massey violated basic safety practices, including not ventilating the tunnels enough. The study supported the federal government's theory that methane gas mixed with huge volumes of explosive coal dust turned a small fireball into a preventable earth-shattering explosion

"The disaster at Upper Big Branch was manmade and could have been prevented had Massey Energy followed basic, well-tested and historically proven safety procedures," investigators wrote.

Virginia-based Massey did not immediately respond. It is in the process of being acquired by Alpha Natural Resources. Massey executives have declined to be interviewed by investigators.

The report, released online at the same time it was presented privately to families of the victims, is the first of several that are expected. State and federal investigators are pursuing their own investigations, while federal prosecutors conduct a criminal investigation.

The 113-page report was compiled by a team led by former federal Mine Safety and Health Administration chief J. Davitt McAteer, who was appointed by then-Gov. Joe Manchin to examine the April 5, 2010, explosion.

McAteer's report has 11 findings and 52 recommendations, ranging from better monitoring of underground conditions to subjecting companies' boards of directors to penalties if they fail to make safety a priority.

'It literally felt like you were melting.' —Roof bolter Michael Ellison

It also offers disturbing details about the conditions in 2.7 miles of active underground mining where air routinely flowed in the wrong direction, if at all. Men were regularly forced to wade through chest-deep water, and the safety inspector who was supposed to file pre-shift reports on air and methane readings did so for weeks before the blast without even turning on his gas detector.

There was so little fresh air flowing to clear away methane, coal dust and other dangerous gases that the normally chilly underground environment grew hot enough to make men sweat.

"It literally felt like you were melting," said roof bolter Michael Ellison, who had called in sick the day of the blast. His shift started at 7 a.m., he told investigators, "and by 8:30, all of us looked like we had been standing out in a rainstorm, just soaking wet."

It was, the report concludes, a mine where the crew could do nothing to save itself when the inevitable happened.

"Everything just went black. It was like sitting in the middle of a hurricane, things flying, hitting you," Tim Blake, one of two survivors, told investigators.

The other, James Woods, was so severely injured he may never be able to talk about what he endured.

Evidence suggests the crew closest to the explosion knew what was about to happen but had little time to react and no way to stop it.

At 2:59 p.m., the operator manually disconnected the cutting machine, a two-step process that investigators say shows he knew something serious was happening.

'Hollered and hollered'

When dust started billowing from the mine, dispatcher Adam Jenkins frantically called underground, reaching only one crew.

"I hollered and hollered and hollered — just, you know, praying and hoping that someone would answer me," he told investigators, "and it never happened."

Blake, meanwhile, struggled in the darkness to save his crew, pulling Woods and seven other men from a shuttle car and putting emergency air packs on all but one, whose device was missing.

"They all had pulse," he said.

Blake checked them a few minutes later.

"Everybody had a pulse but one man."

Then he decided to leave them — "the hardest thing I ever done" — to get help.

On his way, he met Massey employees who had raced into the mine to help. 

"Evidence found during the investigation does not suggest a force of this magnitude," the report says.

The investigators also concluded the mine's ventilation system had been compromised, in part by flooding in tunnels leading to a fan positioned to suck air through the mine, but also by leaky airlock doors that had been propped open and other missing air controls.

Upper Big Branch was cited 64 times for ventilation violations in 2009.

Massey has spent moths blaming the federal government for the blast, claiming that changes MSHA ordered to its ventilation plan only contributed to the problems.

The independent investigators found no evidence to support those claims.

Nor did they find any records showing Massey complained to MSHA.

The mine about 50 miles south of Charleston hasn't operated since the explosion. Massey has proposed sealing the mine, but details still need to be worked out with MSHA.