The mayor of Manitoba's second largest city says he's thankful firefighters were able to contain a massive blaze that tore through Brandon's downtown core destroying a century-old building, a local affordable housing complex and displacing more than 130 people.

Residents of the Massey Manor complex watched their units go up in flames before the building's roof collapsed during Saturday's fire. A century-old building was also reduced to its chimney and foundation and other downtown properties were burnt to the ground.

The Red Cross says 137 people have registered for assistance and are being housed in hotels for the time being.

"Three buildings will, I believe, have been totally destroyed," Mayor Rick Chrest told CTV News Channel on Sunday.

He said he does not expect Massey Manor will be a "total loss," while acknowledging that the 58-unit building sustained significant damage, both from the fire and the water it was doused with.

"It was getting to be a bigger concern about where else this could ha spread, and again I thank all the fire personnel for the containing the way they have done," said Chrest.

Authorities in Brandon said the fire started around noon at the historic Christie's Office Plus building on the 700 block of Pacific Avenue. Embers drifted to Massey Manor, before jumping to Collyer's equipment supply store, a beer vendor, and a vacant dance club connected to a downtown hotel.

A handful of buildings in between were left largely undamaged. The City of Brandon said no fatalities have been reported in a statement on Saturday.

Massey Manor resident Cheryl Cote said she heard what sounded like explosions as she fled from the building through a smoke-filled hallway. Residents stood outside and watched as the building's roof collapsed.

"This girl said, 'The building is on fire. The building is on fire,'" Cote told CTV Winnipeg on Saturday. "I'm happy that nobody got hurt, but I am devastated by that fact that I have to start over."

Emergency reinforcements from outside the city, including firefighters from CFB Shilo, arrived to help battle the blaze. The Red Cross is helping anyone who is displaced find housing. The provincial government and Salvation Army are also working with municipal authorities.

Brandon Fire and Emergency Services Chief Brent Dane said the fire was one of the biggest in the city's modern history.

"The vendor and night club is (burnt) to the ground. Christie's is to the ground," he said on Saturday. "We are trying to still fight the fire in Massey Manor and Collyer's service centre."

The cause of the fire is unknown but authorities are certain it began at the Christie's Office Plus building, with reports of explosions as well.

"There was some explosions that did occur," said deputy fire chief Scott McDonald. "We're not sure the source of those explosions at this time."

The City of Brandon said in its statement that fire and emergency crews will remain on site to extinguish "flare-ups" at impacted buildings.

The Brandon Bear Clan, a community safety organization, wrote on its Facebook page that it is collecting supplies and clothing for those displaced by the fire.

A GoFundMe crowdfunding page set up for those forced from their homes raised over $5,000 in 24 hours.

Cote said it was difficult to stand by and watch her home and possessions go up in flames.

"I lost a lot of personal souvenirs, mementos, things that I wanted to keep," she said.

But the resident said thanks to the work of a spontaneous clothing drive, she now has more clothes to wear and is staying positive.

"Just got to quit thinking about what you're losing and just go forward," she said.

With a report from CTV Winnipeg's Sarah Plowman