Firefighters rescue a man from a fire at the Westlawn Village apartments on Thursday night. (Laura Osman/CBC News)

Firefighters are expected to battle a three-alarm blaze in a west Edmonton apartment building into the early hours of Friday morning.

The fire broke out around 8:50 p.m. Thursday at the Westlawn Village apartments, a three-storey walkup at 165th Street and 96A Avenue. A third-alarm was called at 9:23 p.m.

Flames were seen shooting through the top of the structure and much of the roof collapsed later on. About 60 firefighters were called to the scene.

Crews were able to get the fire under control but about half of the 48 units were heavily damaged or destroyed. Two men were rescued from the third floor.

Deputy fire chief John Lamb said that firefighters will re-enter the building to make sure that everyone got out safely. At one point, the fire was so intense that crews had to be pulled out and the fire was fought from the exterior.

"The roof was starting to come in and the floors are quite spongy. The flames were quite intense and the heat was intense," Lamb said. "So it's a difficult entry so that's why we go to exterior attack."

Residents told CBC News that they heard a loud bang before the fire started.

The Red Cross and disaster services were called to the scene to help displaced residents.

The cause of the fire is still under investigation.