The Cook County Medical Examiner's office today confirmed it had identified some bones found under a disabled semi-trailer truck on Chicago's Far South Side as being human. The bones were wedged under the semi after it was knocked into a water runoff ditch after a minor accident Friday on the Bishop Ford Freeway near the 12200 block of East South Doty Avenue. After the truck was towed out of the ditch, firefighters hosed off the debris and discovered the bones. Authorities said the bones were wrapped in canvas and rope and covered with debris. Chicago Police spokeswoman JoAnn Taylor said Sunday it was not clear whether the remains came from the truck or already were in the ditch, which was several feet deep. The medical examiner's office said further examination was needed to determine the cause of death and to identify the age and gender of the dead person.