A prominent doctor found dead a month ago along a downtown Minneapolis freeway apparently fell to his death in what authorities Thursday are calling an accident in which alcohol played a role.

Dr. Christopher D. Robert, 50, chief of anesthesiology at Hennepin County Medical Center (HCMC), was walking to his downtown residence from a workplace Christmas party sometime before his body was discovered around dawn on Dec. 5 along westbound Interstate 94 near Groveland Avenue, his wife said.

A statement released Thursday by the Hennepin County medical examiner’s office said Robert died of a “blunt-force head injury sustained in an apparent fall.” The statement added that “the manner of death is [an] accident.”

County spokeswoman Carolyn Marinan added that the autopsy determined “acute alcohol intoxication was involved” in Robert’s death.

Police have yet to determine from where Robert fell, department spokesman John Elder said.

“This was an unwitnessed death,” Elder said Thursday. “We have to rely on what the body and the injuries tell us and the medical examiner.”

Robert’s wife, Kerry Ace, an emergency room doctor at Children’s Hospital in St. Paul, said a few days after her husband’s death that he had been walking to the couple’s second home, a condo in the 200 block of 11th Street, from a holiday celebration for the hospital’s anesthesiology department. They also reside in Faribault, Minn.

A 911 caller alerted authorities to his body shortly before 7:30 a.m. The State Patrol quickly ruled out that a motorist had hit Robert and fled.

Robert graduated from Nova Southeastern University in Fort Lauderdale, Fla. He completed his residency training in anesthesiology at the University of Minnesota. Robert joined HCMC in 2003 and was appointed chief of anesthesiology in 2011. Along with his wife, Robert is survived by a son Evan, 19, and daughter, Jennifer, 11.