The sole survivor of the Sago mine disaster was moved out of the intensive care unit at Ruby Memorial Hospital on Tuesday as his condition continued to improve.

Randal McCloy Jr., 26, was transferred to a step-down unit with less intensive monitoring because his condition, while still serious, has become more stable, said Dr. Larry Roberts.

But McCloy, the only miner on a crew of 13 to survive the Jan. 2 explosion and its aftermath, has not yet regained consciousness.

Roberts said McCloy's heart and liver functions were recovering slowly, but he remains on dialysis because of his kidney damage. McCloy, of Simpson, has been breathing without assistance for several days.

Meanwhile, state and federal investigators began interviewing the first in a long string of witnesses Tuesday at a federal courthouse in Clarksburg. The exact number of people subpoenaed was not immediately clear. Nor was it clear how long those interviews might take.

The meetings are being conducted in private, with officials from the Mine Safety and Health Administration and the state Office of Miners' Health Safety and Training. Representatives for Ashland, Ky.-based International Coal Group Inc. also were expected to attend.

Lara Ramsburg, spokeswoman for Gov. Joe Manchin, said public hearings will be held later, probably in March.

Efforts to ventilate deadly gases from the mine also continued Tuesday, and a spokeswoman for ICG said the company does not know when it will be safe for investigators to re-enter and begin collecting physical evidence.

Twelve miners were killed in the disaster. One is believed to have died immediately in the blast, while state officials have said the others died of carbon monoxide poisoning.

They were remembered Sunday, along with McCloy, at a community memorial service in Buckhannon.