(CNN)A woman and three children died when a fire swept through a house in Philadelphia early Sunday, officials told CNN.
The Philadelphia Fire Department responded soon after 2 a.m. to the burning building on Hartville Street, where they found flames coming from both floors of a two-story rowhouse, fire department spokesperson Kathy Matheson told CNN.
There were five people inside the building, Matheson said, including the woman and three children who died. The Philadelphia's Medical Examiner's Office is investigating their causes of death. The office could not be immediately reached for comment Sunday morning.
The fifth person, another woman, escaped by jumping out of the building and was taken to a hospital for treatment.
The fire was brought under control at 2:28 a.m., Matheson said. More than 60 fire department personnel responded to the blaze, Matheson said -- including firefighters, medics, chiefs and support personnel.
The cause of the fire is under investigation by the Fire Marshal's Office.