CHICAGO: A 6-year-old boy who spent more than three hours underground after being swallowed by a massive Indiana sand dune was able to respond to ‘simple commands’ after being flown to a Chicago hospital.

Nathan Reul, who is six, was rescued after falling into a sinkhole that opened up at Indiana Dunes National Lakeshore, trapping him for more than three hours under 11 feet of sand.

Nathan, whose survival was described as a ‘miracle’ by a local coroner, remains in critical condition Saturday at Comer Children’s Hospital and has responded well to being on a ventilator, hospital spokeswoman Lorna Wong said in a statement.–MO

Lakeshore Ranger Bruce Rowe said work crews had to use heavy excavating equipment to pull the little boy out of a dune known as Mount Baldy, where he was playing Friday afternoon. 

Wong later told The Associated Press she could not say if the responses were an indication that he had regained consciousness.

Michigan City, Ind., Fire Chief Ronnie Martin told WSBT-TV on Saturday that an air pocket saved the boy’s life.

According to Bruce Rowe, a ranger at the Indiana Dunes National Lakeshore park along Lake Michigan, the boy’s family said he was playing on the dune Friday when he dropped partially into it.

The 6-year-old was walking with his parents along the sand dunes in Michigan City when he came across a rotted tree that may have caused the collapse, While they were trying to dig him out, the dune collapsed, burying the boy under 11 feet of sand, he said.

The family called 911, and emergency responders were on the scene within 15 minutes and began digging by hand, Rowe said. Crews with excavating equipment were brought in to aid the rescue effort.

Martin told the South Bend, Ind.-area TV station that firefighters located the boy while prodding the dune, right after they detected the air pocket that enabled him to survive for so long underground.

They pulled him out and the boy was rushed to a Michigan City hospital, then later flown to Comer.

LaPorte County Deputy Coroner Mark Huffman told The News-Dispatch of Michigan City that the boy’s survival was a ‘miracle.’

‘It is totally amazing,’ he said.

Authorities were puzzled about the cause of the collapse, which Rowe called ‘unprecedented.’

The section of the dune, which is more than 125 feet high and is known as Mount Baldy, had been cordoned off for restoration work.

It will remain closed at least through the weekend and until authorities can determine if it’s still a danger.

Wong, the Comer spokeswoman, said the boy’s family wanted to express is gratitude to the emergency responders and everyone else who helped in his rescue.

‘They also ask that people include this little boy in their prayers,’ she said.

During a press conference Saturday afternoon, Laporte County Chief Deputy Coroner Mark Huffman told ABC News that the 6-year-old had ingested sand, and he will likely undergo extensive therapy to rehabilitate his lungs.