CHARLESTON, W.Va. (AP) — One of Massey Energy's top executives has traded his power office for the soot-covered depths of the West Virginia coal mine where an explosion killed 29 men.

Chris Adkins, chief operating officer of the S&P 500 coal company, led Massey exploration teams into the Upper Big Branch for nearly a month, spokesman Jeff Gillenwater said. For most of June, teams of Massey, federal and state employees, including Akins, explored the mine to make sure it was safe enough for government, company and union investigators to work without oxygen tanks and free from risk of explosion or fire.

Adkins is still working underground as part of the company's investigation into the April 5 tragedy. The explosion also is the subject of civil and criminal investigations.

"He's our top mining guy," Gillenwater said. "It seems reasonable that he would be involved."

Adkins' salary and bonus totaled roughly $950,000 in 2009, according to company documents, and his stature in the company would allow him to steer clear of such hands-on work in the mine if he wanted to.

"It's unusual, but if you know Chris Adkins it's not that unusual for him," said Ron Wooten, West Virginia's mine safety chief.

Adkins, 44, started working underground for Massey subsidiary Rawl Sales & Processing Co., in 1985. He's worked as a section foreman and later plant supervisor, but long ago graduated to the executive ranks at several subsidiaries and before becoming vice president of Massey's underground production. He only received his certification as a mine rescue team member on May 28.

Besides serving as Richmond, Va.-based Massey's chief operating officer, Adkins is one of Massey's two senior vice presidents.

Adkins isn't a widely recognized public figure, unlike Massey CEO Don Blankenship, who is well known throughout the region for his political activities and the company's high profile.

But Adkins gained some visibility with television appearances to brief the media during attempts to find four of the missing Upper Big Branch victims.

"He played a large role with the families during the rescue operation and the recovery," Wooten said. And Wooten said the families of the 29 victims did not object when Adkins was named to participate in the investigation by Massey. The families did object to other Massey representatives, though he did not name them.

"His name was on there and they were concerned about some people not being on there," Wooten said.

Investigators have begun the process of looking for clues to the explosion. The federal Mine Safety and Health Administration's plan calls for teams to map the mine, take dust samples to determine whether the mine had too much combustible material around, and look for damage patterns that show where the blast might have started, among other things.

Massey has complained about that plan because it is not being allowed to take its own dust samples and photos.

Investigators also have been clearing the mine's rail tracks and repairing electric lines, according to Massey.

Wooten said he has no problem with Adkins' presence either, despite the fact that Massey is the target of the investigation.

"You've got to remember, too, that no one, whether it's federal, state, representatives of the miners, the special investigator or the company, members of the company members of their investigative team are ever to be alone," he said. "It not only has to look right, it has to be right."