A passerby found the baby at about 6 a.m. behind a small wall at the northwest corner of Hardwick Street and Lakewood Boulevard. She was taken to a Long Beach Memorial Hospital in stable condition.
Sheriff's deputies were trying to figure out who the baby belongs to. A child endangerment investigation was ongoing.
Under California law, babies may be dropped off at safe surrender sites, such as hospitals and fire stations, with no questions asked.
Anyone with information is asked to call detectives at Lakewood Sheriff's Station at (562) 623-3500.