More than 100 Burnaby, B.C., residents have lost their homes after fire destroyed an apartment building Sunday morning.

Several people were treated for smoke inhalation in the fire in the 3500-block of Smith Avenue near Canada Way.

Firefighters from three different stations fought the blaze from about midnight, but they were unable to save the wood-frame structure, which collapsed just after 6 a.m. PT.

"When crews got here, it was hairy. You had the fire and people trapped. For our crew, [the choice] was life or structure," said assistant Fire Chief Darrell Smith. "They laddered that building and started getting everybody out of there."

Area resident Cassy Docheff said firefighters did a great job.

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The four-storey building collapsed due to the fire. (Doug Kerr/CBC)

"The firefighters were on top of things and cleared out the building in under half an hour," said Docheff. "Then the building buckled, under all the water pressure, I guess, and just collapsed.  It was just devastating to see all those people watch their lives go up in smoke."

Residents had no time to save any belongings in order to get out of the building quickly.

Ian Shepherd said he had to move so fast he discovered later he'd put on non-matching shoes.

"You just don't want to breathe in smoke and you don't want to get burned. You just want to get the hell out of there," said Shepherd.

Docheff said the fire crews were also rescuing pets.

"I saw a fireman, he was carrying down a doberman and cats."

Cynthia McPhee said her dog wouldn't be alive if it weren't for the firefighters.

"They actually went back into the building and got my unconscious dog and gave him oxygen. He revived in an hour," McPhee said.

Damage is expected to be in the millions of dollars. The cause is under investigation.

With files from the CBC's Deborah Goble and Brian Dance