In a life threatening emergency dial Triple Zero (000)
Storm and Flood Assistance
Firefighters have been forced into a defensive position due to the heat of the fire and partial collapse of the ceiling at the rear of the building.
Crews are searching the first floor to find the source.
The building is heavily smoke logged and more ACT Fire & Rescue units have been called in.
The ACT Ambulance Service also has intensive care paramedics and a duty officer in attendance.
No-one has required treatment yet.