Surgery a success for once-missing Georgia Tech student

A missing Georgia Tech student found bloodied and beaten Monday in a northeast Atlanta ditch made it through a Wednesday spine surgery "with flying colors," his mother posted on Facebook .

Atlanta police, meanwhile, were still waiting to speak with him.

James Hubert, a 24-year-old aerospace engineering major, was reported missing after he didn't return home from a Friday night sorority formal in northwest Atlanta. Monday morning, a group of friends using the "Find My iPhone" app discovered him lying on the railroad tracks along DeKalb and Arizona avenues, near the Kirkwood neighborhood.

Hubert's mother, Didi, previously described his injuries as including left-side paralysis, blood on the brain, broken ribs, a broken scapula, a punctured lung and four broken vertebrae.

Hubert had surgery on the latter Wednesday, his mom wrote on Facebook. At about 5:15 p.m., she wrote that he made it through successfully.

"He's had countless friends and family coming to visit him," Didi Hubert wrote earlier in the day. "This has lifted his spirit immensely. We realize how truly blessed we are for a positive outcome considering so many don't end this way."

What happened to Hubert remains a mystery, at least officially.

Authorities have praised Hubert's friends for finding him , but otherwise remained mum on the incident. The investigation remains open, but Atlanta police spokeswoman Officer Kim Jones said Wednesday morning that detectives had not yet been able to interview Hubert "about the circumstances over the last few days."

Hubert's mother has said he left the sorority formal alone and was taking MARTA home when he was "jumped, beaten up, robbed and left for dead."