Winnipeg fire crews are still on scene battling a fire in the 500 block of Roseberry Street that began on Monday.

The city said the fire is in a two-storey commercial building, and no one was inside.

A large plume of smoke could be seen coming from the fire across the city during rush hour Monday.

Mark Reshaur, assistant chief, Winnipeg Fire Paramedic Service, told CTV News the fire was well involved when crews arrived, and they attacked it defensively.

“It’s a waiting game, we’re just drowning it at this point,” he said. “The fire is burning very vigorously, that’s not unusual in a defensive fire. Right now we’re having to stand back and just pour water on it.”

Reshaur said the building is a warehouse where some walls and the roof had collapsed due to the fire, so crews couldn’t go inside.

He also said working in the cold is a challenge for firefighters.

“It’s a big challenge for us, we gotta be paying close attention to the health and welfare of our people,” he said, adding that they’re on the lookout for frostbite and hypothermia.

The warehouse’s landlord told CTV News there were three businesses on the lower level of the building.

“There’s a filter company with filtration and exhaust products. Then in the centre is furniture, chairs and furniture equipment for hotels and restaurants,” the landlord said. “And in the north unit, that’s a print shop.”

He said the warehouse is only partially insured.

“It’s terrible. This has been our business for 41 years. So this is 41 years of my life going up in smoke,” the landlord said.  “I’ve never had a fire claim in my life and I’ve owned properties since 1972.”

Meantime, United Firefighters of Winnipeg president Alex Forrest told CTV News he was concerned about other hazards.

Forrest said there have been reports of deep black smoke and smoke that is “all the colours of the rainbow.”

He said smoke like that tells him it’s “extremely toxic,” and that the dozens of firefighters working there are wearing full protective equipment.

There is no damage estimate yet. Forrest said it is unknown whether the building will have to be torn down or not.

Meanwhile, Manitoba Hydro said the fire did some damage to power lines. A spokesperson said 12 customers were affected. As of late Tueday morning, seven addresses on Roseberry were still without power.

Crews will likely not be able to access the building until early Wednesday morning as the fire continues to burn with a risk of the exterior walls collapsing.

With files from CTV's Sarah Plowman and Renee Rodgers