She was laying in a hammock on the roof of a Charter Street building with one end attached to the chimney that collapsed, according to Boston Fire Department. Another person in the hammock at the same time was not injured.
BFD used a ladder truck to transport the woman from the roof, who was later taken to the hospital for treatment. The Charter Street building where the incident occurred is located near the corner of Salem Street.
Here is a photo of the chimney, courtesy of Peter Wilson, @PetesWire:
— Peter Wilson (@PetesWire) July 11, 2017