The 6-year-old boy who spent more than three hours trapped beneath 11 feet of sand remained in critical condition Sunday night at the University of Chicago Medicine Comer Children's Hospital, according to hospital spokeswoman Lorna Wong.
Nathan Woessner was rescued Friday after being swallowed by a sand dune at the Indiana Dunes National Lakeshore on the Lake Michigan shore in Michigan City.
A recording of a 9-11 call obtained by NBC News reveals that the boy's father and a family friend attempted to dig Nathan out before emergency personnel arrived. It took rescue teams and private excavation crews more than three hours of digging on the western slopes of Mt. Baldy to rescue him.
Michigan City Police Chief Mark Swistek told The News-Dispatch that Nathan's parents said the child was "doing well."
Swistek told the newspaper that the parents "are upbeat and hopeful."
"They are watching him [Nathan] closely and hoping to speak with him in the next few days," he said.
Mark Baker, Michigan City Fire Department spokesman, also told The News-Dispatch that he learned Nathan did not suffer any life-threatening injuries, nor did he receive any brain injuries from a lack of oxygen.
Officials said Nathan was able to respond to simple commands as well as mechanical ventilation when he arrived at the hospital.
Rescue crews were called to the scene shortly after 4:30 p.m. local time said ranger Bruce Rowe, a spokesman for the National Park Service. The boy was found around 8:05 p.m.
The dune that entrapped the boy was at an area of the park closed for restoration.
Two private excavating companies joined with La Porte County emergency workers, Northern Indiana Public Service Co. workers and National Park Service officers to dig out the boy.
"This has not happened before, and we will certainly not let people on the dune until it is safe," Rowe said.
NBC News' Tracy Jarrett, M. Alex Johnson and Christopher Nelson contributed to this report.