Authorities were unsure whether the woman's death resulted from the fire. The Delaware County Medical Examiner's Office is expected to release her identity and cause of death today.
"At this point, we have not made a positive identification," Lt. George Rhoades of the Upper Darby Police said.
The fire broke out about 11:40 a.m. on the 200 block of Kingston Road. Police said the fire originated on the second floor of the duplex and reached two alarms before it was declared under control. Authorities said the second floor was severely damaged, and the structure had been rendered uninhabitable.
Police said that about 8 a.m. a woman on the block had called 911. The woman was screaming. Police responded and found no one, Rhoades said. That woman's car is missing, he said.
