No one knows how the uncommunicative teenager got there after being missing two days, The Chicago Sun-Times reported.
Kahil Gray disappeared Tuesday while at the hospital with his father to pick up forms. The newspaper said hospital video shows him running north on Cottage Grove Avenue.
Two days later, Mary Olander of Morton Grove spotted Kahil on a bike path and recognized him from news coverage. She called 911.
His mother, Beryl Gray, hadn't slept in two days when police called her to say her son had been found safe and sound, the Chicago Tribune reported.
Her son said, "Hello Mommy," his mother said. "I said, 'Kahil I'm so happy, I love you,'' and he said, 'I love you too.'"
Khalil was checked out by paramedics and appeared in good condition, Glenview Police Cmdr. Don Hohs said, but he was taken to Glenbrook Hospital for an evaluation.
Hohs said he has no idea how the boy, who can speak only a few words, got to Glenview. His mother said she doesn't know either, the newspaper said.