THE worst US coal mine accident in four decades, in which 29 miners died, was manmade and could have been avoided if mine owner Massey Energy had followed basic safety measures, an independent investigation concluded in a report that was published yesterday.

Massey shares dropped 2,3% to $60,38 on the New York Stock Exchange. Stock in Alpha Natural Resources, which is acquiring Massey, fell 2,8% to $49,73.

The report on last year's Upper Big Branch blast found Massey miners lacked training in safety or in recognising hazards, and it called for tougher enforcement powers for federal and state mine inspectors.

"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," says the report, ordered by Joe Manchin, governor of West Virginia at the time of the blast.

"A company that was a towering presence in the Appalachian coalfields operated its mines in a profoundly reckless manner, and 29 coal miners paid with their lives for the corporate risk-taking," it says.

"The company broke faith with its workers by frequently and knowingly violating the law and blatantly disregarding established safety practices."

It did not mention names, such as that of former CE Don Blankenship, who headed Massey for years when it received many safety violations warnings from federal regulators. He has since retired.

A separate investigation of the March 5 2010 accident by the federal mine safety and health administration is still under way.

The independent investigation, headed by Davitt McAteer, cited failures in ventilation, rock-dusting standards and machinery maintenance, and said mine safety practices failed to keep pace with modern mine production technology. The report was released online before families of the dead miners were briefed on the findings.

Massey said in response that it agreed the industry needed to examine whether it could achieve better methane monitoring technology.

"(But) we disagree with Davitt's conclusion that this was an explosion fuelled by coal dust. We believe the explosion was caused by a massive inundation of methane-rich natural gas," the company said.

The blast at Massey's mine near Montcoal, West Virginia, was the deadliest US mine accident in four decades. Massey posted four consecutive quarterly losses following the blast because of stalled production at several mines.

The company also struggled to recover from the negative publicity.

It has agreed to be acquired by Alpha Natural Resources in a deal valued at about $7bn that is expected to close before the end of next month. As part of the takeover, Alpha would assume liabilities related to the accident.

Massey said last week that 13 of the victims' families had filed wrongful death suits, while eight families had signed settlements. In addition, four employees had sought redress for alleged emotional distress. Massey estimated litigation settlements would total $78m. Reuters