ATLANTA (AP) — Police continue to investigate what happened to a Georgia Tech student found injured along railroad tracks in Atlanta three nights and two days after he disappeared from a party.

Friends who found 24-year-old James Hubert by tracking "pings" from an iPhone say he told them he was robbed and beaten after he left the sorority party Friday night.

Emma Jeffery told WXIA-TV that she and other friends found him without his shoes and his wallet was gone. She said he told her he was beaten by a group of men.

Atlanta police Lt. Charles Hampton told WSB-TV that Hubert hasn't been coherent enough to tell detectives what happened from the time he left the party until he was found after sunrise Monday. He was being treated at Grady Memorial Hospital.