MICHIGAN CITY, Ind. — A 6-year-old boy who survived being buried for three hours after a sand dune collapsed is moving around the Chicago hospital where he is recovering and could be released soon, his doctor said Monday.

Nathan Woessner, who was in a coma after being buried by a dune in Indiana, "is listed as in good condition and continues to improve," Dr. Diana Mitchell said in a statement released by Comer Children's Hospital.

She said the boy, who lives in Sterling, Ill., returned to a regular diet on Monday, "and can leave his room to visit the playroom."

Nathan was buried for more than three hours July 12 in the dune called Mount Baldy at Indiana Dunes National Lakeshore, about 40 miles southeast of Michigan City. He is expected to make a full neurological recovery but may suffer lingering lung problems from inhaling sand, doctors have said.

He was removed from a ventilator last week. When the boy was intubated, two front teeth that had been loose were knocked out, said his grandfather, Don Reul.

"We're saving them for him, and they're going to put them under his pillow at some point," Reul told The LaPorte County Herald-Argus newspaper.

Nathan sustained scrapes on his face and a cut on his head that required more than 20 staples, and his each of his corneas was scratched from the sand, his grandfather said.

"The ophthalmologist has been in, and they don't see anything (serious). His motor skills are good so there doesn't seem to be any damage in that area," Reul said. "He's coming along at a rapid rate in his recovery, so we're just really happy about where things are and how they're progressing.

Since coming out of a coma and starting to speak to relatives, the boy has not mentioned his entrapment, the grandfather added.

"He hasn't had any recollection so far that he's told us about, and we're hoping that he has none," Reul said.