Firefighters continue to deal with hot spots in a building on 1st Avenue NW but it's now believed that the worst is over.

Crews were sent downtown around 6:24am and quickly deployed the hoses and started battling a blaze in a building just south of the corner of 1st NW and High Street. The brick building shares the alley with Mosaic Place and is believed to be 100 years old.

Emergency crews on scene tell us the fire started on the fire escape on the south side of the building and then spread to the rest of the building. Firefighters have been pumping a large amount of water into the building since they arrived on scene. Just before 8am, flames started escaping from the roof, sending large amounts of smoke over the downtown core.

Our reporter on the scene tells us that firefighters appear to have the situation under control and are working on preventing damage from spreading to a building to the north. Firefighters have told they are now dealing with hot spots inside the building.

Apartments and businesses in the area have been evacuated and traffic is blocked in all directions. Stayed tuned for the latest.

Click here to see pictures from the scene.