TALLMANSVILLE, W.Va. -- Pete Rutherford pushed through a tangle of thorns and fallen branches until the lightning-shattered yellow poplar tree came into view.

	Martha Rial, Post-Gazette The yellow poplar tree that was struck by lightning on Jan. 2. Click photo for larger image.

The poplar stretches a crooked 70 feet skyward, and ends in a jagged break. Down the side, a lightning bolt's slash has stripped out a corkscrew swath of bark, sending long shards and splinters in a 50-foot radius.

"That would have been a real show if you'd been out here to watch it," said Mr. Rutherford. "That was some force."

The shattered tree, once the highest on the hillside along the Rutherford Farm, has become ground zero in the debate over what caused the explosion that roared through the Sago mine Jan. 2.

All sides agree that a lightning strike of 101 kiloamps -- four times the average strength of a bolt -- hit the poplar at the moment a pocket of methane exploded behind a sealed area inside the mine, more than two miles away. The blast killed one miner outright and trapped 12 others, 11 of whom slowly died of carbon monoxide poisoning.

What no one has been able to explain is how a bolt of lightning found its way from the top of a hillside, stretched a mile down the road, crossed the Buckhannon River and made it 13,000 feet into a coal mine, past a set of block walls that were supposed to shut off an abandoned section of mine.

"It's possible," Mr. Rutherford said. "If I was guessing, I wouldn't think the lightning done it, but who knows?"

Possible, yes. But investigators probing the Sago disaster want an absolute answer, and the search for one has led from the traditional theory of a roof collapse creating a spark to the eclectic realms of science, at points hunting for ways a lightning bolt can create magnetism and, in turn, ignite a pocket of gas without making a spark.

International Coal Group, the mine's owners, released what it termed "preliminary findings" that contend the lightning strike set off the methane blast. It cited findings by an independent monitoring group that noted a lightning strike, reports of seismic activities in the area and an alarm on the mine's carbon monoxide monitor, all at precisely the same moment: 6:26 a.m. Jan. 2.

The release of conclusions by ICG in the midst of an ongoing government investigation caught both federal and state agencies by surprise. Yesterday, West Virginia Gov. Joe Manchin III, pressed about ICG's release of its findings more than a month before public hearings, pointedly noted the different course the government investigators have taken.

"Let's just say that we have decided to do it differently as a state and I think the feds have, also," said Gov. Manchin. ICG representatives, he added, "are going to have to speak on why they did what they did and the timing decision of why they did it."

To date, ICG has refused to release scientific details of its investigation and has instructed experts it hired to examine the blast not to speak publicly. Charles Snavely, a company vice president, speaking through a public relations agency hired to buffer company officers from public inquiry, said last week the company had no plans to release a further report explaining how they decided on lightning as the explosion cause.

That could change today, when ICG officials, as well as two of the experts it retained, Tom Novak, a professor of engineering and lightning specialist from Virginia Tech, and Stephen Gerard Sawyer, a consultant, take the podium.

After ICG released its preliminary findings, the West Virginia Office of Miners Health Safety and Training assigned Roy S. Nutter Jr., a professor of engineering at West Virginia University, to explore a complicated theory that the lightning bolt created a pulse of magnetic waves that could have created a corona discharge, a type of electrical discharge that could have ignited methane.

A two-page memorandum, sent April 26 to Randall Harris, an official with the state mining office, cited various works, including a 2005 paper on "Corona-Discharge Initiated Mine Explosions" by Mr. Novak and a colleague, H.K. Sacks.

Mr. Rutherford, who has farmed the hillside overlooking Sago since 1972, said a stream of investigators who came to his farm have pointed to an underground telephone cable that runs barely 50 feet from the base of the stricken tree, then crosses a gravel road via overhead wires, returns to the earth and moves down toward Sago Road.

From there, it would have to travel close to a mile to reach the mouth of the Sago Mine, and move another 13,000 feet into the earth to reach the sealed area where the methane ignited.

Among those expressing doubts about lightning is J. Davitt McAteer, who heads up the West Virginia portion of the joint state-federal investigation into the disaster.

Similarly, James Dean, head of the West Virginia mine safety office, is still perplexed about what conductor could have reached through the mine and into the sealed area when all metal connections, from mine car rails to the metal screen laid over the mine roof, had been cut away before the seals went in.

"What we're looking for is that electrical connection," said Mr. Dean, whose office has sought out the study into the idea of a magnetic pulse creating a sufficiently powerful field to ignite methane.

Investigators for both the government and International Coal Group, the mine's owners, have trekked up the hillside at the Rutherford Farm, visits that began two days after the explosion.

"They came and surveyed, marked splinters, took resistance readings on the junction box for the telephone," Mr. Jones said. "They were even up on top of the hill."

At the hilltop, the researchers checked on high-tension wires that cross another part of the farm and eventually feed power to the Sago Mine.

As for the tree, Mr. Rutherford predicted it will stay up for a while, though the lightning appears to have killed it.