Oxygen ignited inside a special hood worn by a prematurely born infant in a hospital, burning the boy's head and face and leaving him in critical condition. The newborn was lying in an open-topped bassinet under a warmer at Mercy Hospital in suburban Coon Rapids on Tuesday when the accident happened, Allina Hospital and Clinics said in a statement. The baby was wearing an oxygen hood, a device that fits over the face to supply additional oxygen, when something caused the gas to ignite, the statement read.

Nurses who were with the baby immediately put out the fire, Allina said. Authorities were investigating how the fire started.

The baby, born three weeks early, was taken to the burn unit at Hennepin County Medical Center. Officials there Wednesday said he was in a medically induced coma and on a ventilator. He was in critical but stable condition.

Dr. Leslie Smith said the infant will probably survive. But he suffered second- and third-degree burns over nearly a fifth of his body, including his head, shoulders, part of his face and the tops of his hands, Smith said.

Hospital officials and the attorney did not release the name of the baby or identify his family.

Chris Messerly, an attorney for the newborn's family, said that the fire shouldn't have happened, but that the family is focused on letting their baby heal and is not yet considering legal action.

"The family is doing remarkably well under the circumstances," Messerly said.