Massey Energy Co.'s chief executive said yesterday that the April explosion at the Upper Big Branch mine in West Virginia was caused by natural occurrences and not from unsafe coal mining and ventilation procedures.

The explosion that killed 29 miners was caused by a buildup of natural gas, likely from below the mine's floor, that came up through a crack in the floor, according to Massey CEO Don Blankenship. He said that the conclusion was based on new evidence gathered by the company.

This rare natural occurrence contradicts the theory that the blast was caused by methane gas released from the coal seam being mined because of unsafe mining procedures. An analysis of gas emissions near the area of the explosion found that the gas was likely not from coal, according to Massey.

The finding "illustrates that it's something unusual, that it's more likely than not that it came out of the floor ... and not out of the natural mining process," Blankenship said at a mining industry conference in New York yesterday.

U.S. Mine Safety and Health Administration spokeswoman Amy Louviere would not comment on Massey's statements. The federal agency has threatened to take control of the mine as tensions between MHSA and Massey have escalated since the April explosion.

Louviere instead said that MSHA "continues to conduct its investigation, and we feel confident that we'll arrive at the cause of the explosion by the time the investigation has been completed" (Kris Maher, Wall Street Journal, Nov. 18). -- AP