The female tells detectives that around 4:20 p.m. she was going to her front door on the 900 block of Oak Lane Avenue when a male came up to her and asked her for her cell phone.
She said no and he grabbed her and pulled her into an alley.
He started to pull her clothes and punched her in the face until she was knocked out.
A passerby found the teen and called 911.
She was taken to St. Christopher's Hospital for Children.
Police are investigating if she was raped while she was unconscious.
The police are looking for the suspect.