Dozens of firefighters are on the scene of a three-alarm blaze that broke out at Pusateri's Fine Foods in North York on Saturday night.

Fire crews were called to the grocery retailer's Avenue Road location near Lawrence Avenue at around 8:45 p.m. and heavy smoke could be seen throughout the building.

At the height of the blaze, as many as 60 to 70 firefighters and at least 15 trucks were on scene and the fire was knocked down sometime before 10 p.m.

“The fire seems to have started on the main floor,” Toronto Fire division commander Bob O'Halloran said Saturday, adding that they have not yet determined exactly where or how the fire started.

"It is still not completely out... the smoke has dissipated a lot." 

Three people were inside the building at the time of the fire but all occupants managed to escape unharmed.

Frank Luchetta, president of Pusateri's Fine Foods, told CP24 that the store was closed at the time of the fire.

"When I got here they told me the cleaners were inside the building and they smelled smoke and they called the fire department right away and they exited."

He said that he does not know how the fire began.

"At this point, I have no idea," Luchetta added.

O'Halloran said that due to the damages, there will likely be an investigation into what caused the fire.

“I have no estimate of how much damage there is dollar-wise but from what I saw when I looked in, the place is full of smoke," he said.

"There is a lot of water damage around the place as well." 

Toronto police are also on scene and have shut down Avenue Road, between Lawrence and Douglas avenues.