The sole survivor of the West Virginia coal mine explosion remains in critical condition but he is showing signs of improvement, doctors said Sunday.

Doctors treating Randal McCloy Jr., 26, who remains in a drug-induced coma to allow his brain to rest, say his heart and liver are functioning well and his CT scans are showing improvement but that his kidneys have not recovered.

"But this is not unexpected," said Dr. Larry Roberts, the head of McCloy's treatment team at West Virginia University Hospital, explaining this was an anticipated reaction to dialysis, which flushes out the system.

"He'll get that again today and probably every day until the kidneys hopefully do make a recovery," Roberts told reporters at a briefing.

Doctors plan to ease McCloy's sedation on Sunday, a day after he returned from treatment at Allegheny General Hospital in Pittsburgh.

"All of the transport and then the variety of studies and things that we've done to Randy since he's returned here has necessitated maintaining him on sedatives and so it's been very difficult to allow him to awaken, although that is our hope today," Roberts said.

In recent days, McCloy's eyes flickered and he bit down on his breathing tube when his medication was eased.

McCloy, of Simpson, W.Va., was rescued early Wednesday after being trapped in the Sago Mine near Tallmansville, W.Va., nearly two days. The other twelve miners who were with him died.

McCloy was transferred to Pittsburgh on Thursday for treatment in a hyperbaric chamber, which is designed to pump the body with oxygen to battle the effects of carbon monoxide poisoning.

On Saturday night, still under heavy sedation, McCloy was flown by helicopter back to West Virginia University's Ruby Memorial Hospital in Morgantown, so he can be closer to his family.

McCloy's wife Anna, who was also at Sunday's briefing, extended her thanks for the outpouring of support she has received throughout the ordeal.

"We're glad to have Randy back home in West Virginia where he will receive the best care and be surrounded by people who care about us and our children which is so important," she said.

Meanwhile, friends and families of the other victims began grieving Saturday in private visitations, with funerals scheduled Sunday through Tuesday.

After their profound grief was played out in front of television cameras when they discovered their loved ones were dead, short hours after they had been told they had survived the blast, the families took pains to grieve in private.

Police cars lined up to keep television trucks, journalists and others away from the visitation for 28-year-old David Lewis in Philippi. Meanwhile in Buckhannon, two state troopers guarded the entrance to a funeral home where the visitation for 51-year-old Alva Bennett was being held.

Carbon monoxide intoxication will be listed as the cause of death on the death certificates of the other miners trapped in the Sago Mine with McCloy, John Law, a spokesman for the West Virginia Department of Health and Human Resources, said Saturday.