The fire, which broke out at the Canora Gardens residence on 151st Street and 101st Avenue, was brought under control around 3 p.m. MT.
The fire appeared to be on the second floor of the residence and crews were fighting the fire from inside and outside.
After performing an extensive search of the building, firefighters were able to confirm that no one was left inside.
Fire officials could not confirm if the person who died was male or female. At least four, possibly six residents, were taken to hospital.
About 100 people live in the building, and many have decreased mobility and medical conditions that made it challenging for firefighters to get them to safety.
"We executed multiple rescues from several different locations — from windows, from stairwells, from suites," said district fire Chief Randy Shakura. "We've been pulling them from just about every location in the building."
'We are such a close-knit family here'
Resident June Mosher said the fire alarm went off as soon as she arrived back at the building after attending a lunchtime barbeque. She worried about getting her medication that was upstairs in her suite.
"I was crying a while ago but I got myself together. What's the sense in crying, it can't help you," she said. "It's just where are we going to live?"
Mary McEwan says her son ran up the stairs of the building — first to get her out and then to retrieve her walker. He went back one more time to get a lady who was struggling with a walker on the third floor.
"And he come down and he just flopped on the grass and he could hardly breathe," she said. "But then he went upstairs to get the other lady."
McEwan became choked up when she learned that someone died.
"We are such a close-knit family there," she said. "You may not know their names but you know, you just say, 'Hi, good morning, how are you?'"
Cause still undetermined
Residents gathered at a church across the street from Canora Gardens. Linda Larotonda and Caroline George, who were taking a caregivers course at the church, helped pass out glasses of water.
"Just walking around, making sure everyone's OK," George said. "A lot of people are really upset and and in shock."
George talked to one man who was upset that his beloved pet bird may have been lost in the fire. He left his suite to make a quick trip to a nearby grocery store and when he came back, the building was on fire.
The Red Cross is assisting residents and has helped place them in an Edmonton hotel.
Police say it is still too early to determine the cause of the fire.
Roads in the area could be closed for up to 24 hours with limited access given to people to live in the neighbourhood.
Anyone worried about loved ones who live at Canora Gardens can call the Greater Edmonton Foundation at 780-482-6561.