A Wednesday morning fire in a first floor apartment at the Kaufman Lofts in downtown Kitchener was caused by a discarded cigarette, fire officials say.

"The fire was first noticed by someone who was walking on King Street and seeing flames coming out of the window of this unit," said Doug Voisin, platoon chief with the Kitchener Fire Department. 

Emergency services were notified of the fire at 9:44 a.m. Voisin said that when firefighters entered the apartment they found thick smoke, flames and moderate heat.

Kaufman lofts fire

The fire was noticed by someone walking by the building on King Street. (Melanie Ferrier/CBC)

"They were able to knock the fire down very quickly," he said, adding that the fire was confined to one apartment.

No one was in the apartment at the time of the fire, but firefighters did rescue a small dog.

"Fortunately, the dog was very low to the ground in a crate and it's a small dog, so hopefully it didn't suffer a lot of smoke inhalation," Voisin said. 

He said investigators are trying to determine what caused the fire, which appears to have started in a central area of the apartment, not the kitchen. 

Investigators are also trying to determine why the building's fire alarm system was not activated by smoke coming from the fire.