Hamilton firefighters responded to a multiple alarm blaze on Nisbet Boulevard in Waterdown Friday afternoon.
Heavy black smoke could be seen billowing from the second and third floor of a townhouse, with flames spreading all the way to the attic and on to the roof.
Fire information officer Claudio Mostacci noted while crews battled the fire, now deemed under control, that the flames had spread to several units within the complex.
Firefighters in the process of conducting overhaul.
Motacci says there are no reported injuries.