A major fire at a southside Edmonton apartment building has left about 85 tenants out of a home.

The fire gutted the top floors of the north end of the building. (CBC)

"All we got was the cat," said tenant Ryan Gertridge, "but that's all we got."

Gertridge said the fire started in the suite above him.

The upstairs tenant said he went across the street to the store and when he came back the apartment was already burning, said Gertridge.

"The whole third floor was gone up in 20 minutes, like a matchbox pretty much," he said.

Firefighers finished mopping up the fire at Greenfield Apartments, at 114th Street and 40th Avenue around 5:30 a.m., Thursday.

Firefighters inside the building called Mayday when roof threatened to collapse. (CBC)

That fire started around 8 p.m. with all of the residents in the 29-unit building getting out safely.

But there were some tense moments when a group of firefighters sent out a Mayday call.

They were battling the fire inside the building when it appeared the roof was about to collapse.

Firefighters escaped safely

They were able to navigate their way out safely.

Firefighters then changed tactics, concentrating on fighting the fire from outside.

It took firefighters until 3 a.m. Thursday to declare the fire out.

Tenant Ryan Gertridge describes where the fire began. (CBC)

Many residents are being housed by the Red Cross as they search for new places to live.

"My mother just died at the end of May, so I want her pictures," said an emotional April Williams. "Everything's gone and I'm homeless again."

Fire Rescue doesn't know how many suites were destroyed, but they believe a firewall in the building may have saved some of the units.

Investigators arrived to the scene Thursday to figure out what caused the fire.

This comes less than a month after that devastating fire at Heatheridge Estates further south.

That fire caused $13 million worth of damage.