The two-alarm fire on Clayton Street was reported shortly before 2 p.m., bringing multiple fire departments to the scene.
Firefighters were initially unable to enter the home due to the heavy flames and smoke, officials said.
After the fire was under control 30 minutes later, officers and a city resident assisted in pulling three juveniles and an adult female from the back of the house, according to a news release from Mayor Thaddeus Kirkland.
The woman was pronounced dead at the scene, authorities said.
The identities of the fire victims are not yet known.
The cause of the fire is being investigated by the Chester fire and police departments, the Delaware County CID, and the Pennsylvania State Police.
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