An apartment fire that killed 58-year-old Gatineau woman Lynn Legault on Thursday was caused by an electrical problem, Gatineau police say.

The fire sent two other people to hospital and left more than 20 people homeless.

Legault died of asphyxiation due to carbon monoxide, police said Friday.

Firefighters responded at about 3:45 a.m. Thursday to 50 Robinson St., near the intersection of Maloney Boulevard and Bellehumeur Street.

Flames were seen shooting from the windows of the apartment building when firefighters arrived.

Crews used ladders to help rescue tenants from upstairs apartments, including Bruno Grenon, who said he woke up to smoke in his apartment.

Lynn Legault, 58

Lynn Legault, 58, of Gatineau, died after an apartment fire on Thursday morning.

"I checked to see where it was coming from, I noticed it was coming from the apartment below," Grenon said.

"I woke up my two roommates and I tried opening the door to the apartment, but I noticed there was too much smoke for me to get out. So I blocked the door and I started banging like crazy on the window, yelling that we were stuck up there."

Three people were taken to hospital with unknown injuries, police said. The two others have since been released from hospital.

The Canadian Red Cross was on site helping the more than 20 people who will be homeless for at least the next three days.