Two human bones were found washed up on the shore of the Delaware River at Penn Treaty Park in Fishtown on Sunday, investigators said.
A pedestrian called police just after 5 p.m. to report the discovery of a femur – the thigh bone – and a tibia, a lower leg bone.
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The bones appear to be from an adult, Philadelphia Police Inspector D.F. Pace told NBC10. They were taken to the Medical Examiner's Office. No clothing was found nearby.
At this point, investigators said they know very little about the bones. The sex, race and age of the person are unclear, and investigators have not determined how the bones ended up in the river. However, it's believed the person was dead "for some time," Pace said.
"It’s unclear whether or not there was a criminal incident that precipitated this," Pace told NBC10. "So at this point now it's just a matter of conducting a forensic examination and trying to determine who these bones might belong to."