Part of a detached two-storied house in Milton caught fire and filled a portion of the neighbourhood with smoke around noon today.
Individuals are known to have evacuated safely.
The blaze at a unit on Dolby Crescent - at Derry Road and Trudeau Drive - prompted a response from the Halton Police and paramedics, including 16 firefighters and four trucks.
A heavy smoke on the horizon was seen by firefighters when leaving the station at James Snow Parkway.
The fire has been extinguished but officials continue to attend to the scene.