Police are investigating a unit fire in St Marys last night.
About 8.50pm, emergency services were called after reports of a unit on fire on Putland Street, St Marys.
Officers from St Marys Local Area Command and Fire & Rescue NSW attended and were informed a woman was still in a top floor unit.
Officers entered the unit and a woman believed to be in her 70’s was assisted to evacuate.
About 12 people were evacuated from neighbouring units as a precaution.
The fire was extinguished and a crime scene has been established at the location and will be examined by forensic specialists
A 25-year-old woman was treated by paramedics for smoke inhalation no other persons were injured as a result of the fire.
An investigation has commenced to determine the cause of the fire.