UPDATE: Terrianna Wilson was found just before 9 a.m.
A Portage Park grandmother on Wednesday morning said she woke up and discovered her young granddaughter was missing.
Michelle Wilson said she woke up at about 2 a.m. and found the front door open to the apartment on the 4700 block of West Grace Street.
Wilson said her 4-year-old granddaughter, Terrianna Wilson, had previously walked out of the apartment about three months ago. She was later found by a neighbor.
Wilson said she had already searched the neighborhood by 8:30 a.m. Officers from the Chicago Police Department and K-9 units were added to the search and were going door to door.
The grandmother said the girl has been diagnosed with Attention Deficit Hyperactivity Disorder.
Wilson has custody of the girl and said she doesn't think the 4-year-old's mother or father would have taken her.