Thick black smoke could be seen billowing from a patio furniture store just southwest of Puslinch.
Fire officials said the call came in just before 3 p.m. Saturday at Flamborough Patio Furniture.
As many as 30 firefighters responded and worked to contain the fire from spreading to nearby buildings, including a home which was affected.
Hamilton fire said the furniture building collapsed and fire trapped under it is still burning.
People were inside the home that sustained damage, but managed to escape unharmed.
The initial building has collapsed. The other two buildings have suffered some damage but firefighters did an amazing job being able to keep the fire away from those buildings," said Claudio Mostacci with the Hamilton fire department.
Ontario Provincial Police were also on scene assisting with traffic.
"Really the reason we are here is to make sure the charged fire hoses are not obstructed or not run over. Once they're off the roadway all lanes will be clear," said Const. Graham Williamson.
It is not yet known what caused the fire and officials said it is too early to estimate the cost of damage.
With reporting from CTV Kitchener's Leena Latafat
