One person is dead and one person is injured after a fire tore through a highrise residential building in North York on Friday night, Toronto Fire officials say.

Firefighters found a body on an eighth floor balcony early Saturday when they searched the 15-storey building at 235 Gosford Boulevard, near Jane Street and Steeles Avenue West, during the five-alarm fire.

"We've isolated that the fire originated in apartment 808 and there was one victim located on the balcony of that unit," provincial fire investigator Rick Derstroff said at a news conference Saturday afternoon.

The victim's identity has not been released.

Derstroff said a post-mortem will be done but a date has not yet been set.

Toronto Fire officials say building has been evacuated and it is not known when the approximately 700 residents will be able to return.

Death being treated as suspicious

Toronto Fire Deputy Fire Chief Tony Bavota said the body was found after 1 a.m.

"When we were able to achieve an upper hand on the fire, that allowed us to be a little bit more systemic in the work that we were doing," he said. "Some secondary searches were conducted and some investigations, at which point, a body was located on one of the balconies."

Toronto police say they are treating the death as suspicious until they can determine the cause.

During the fire, some terrified tenants went out on their balconies where witnesses said they could be heard screaming for help.

Icicles have formed on the balconies where firefighters sprayed water on Friday night. (Yanjun Li/CBC)

Toronto paramedics assessed six people at the scene and took one to hospital in serious condition. That person is now in stable condition.

Fire was burning on 6 floors at its peak

Emergency crews were first called to the scene at about 5:30 p.m. on Friday night. The fire, brought under control by about 8 p.m., was deemed officially out at about 3:10 a.m. on Saturday, according to Capt. David Eckerman, spokesperson for Toronto Fire Services.

At its peak, the fire was burning on six floors, but was concentrated on the seventh, eighth and ninth floors.

"It was an extremely difficult fire for our staff to fight," Bavota said. "That was coupled with the fact that the elevators weren't working. All of the work that was done here last night was up and down the staircases."

Toronto firefighters help tenants to leave a highrise building on Gosford Boulevard in North York where a five-alarm fire seriously injured one person and damaged several floors on Friday night. (Jeremy Cohn/CBC)

Bavota said no reports of anybody missing or unaccounted for were filed during the fire.

The fire department also did not receive any reports of a person on a balcony screaming for help, he added. Officials have not released the sex and age of the person who died.

Much smoke and water damage has been done to units and their contents and hallways on affected floors, he said. The property owner is bringing in structural engineers to inspect the building on Saturday, he added.

Efforts underway to help displaced residents

According to Toronto police, efforts are underway to help displaced tenants. Residents were asked to stay with friends and family.

Dozens of firefighters, police officers, paramedics and TTC officials were on hand to help tenants leave the building after midnight. Crews went floor by floor to move people out and the evacuation process took a few hours.

Tenants used several TTC buses for shelter and some people slept on the buses.

A line of TTC buses was ready to provide shelter to residents forced out of the building because of the five-alarm fire. (Jeremy Cohn/CBC)

About 49 people sought shelter overnight at the nearby Driftwood Community Centre, 4401 Jane St. The centre, which has cots, is providing food and water.

On Saturday, Charles Jansen, director the city's Office of Emergency Management said that about 100 have so far registered at a reception centre that has been set up there.

'There's nowhere to go to live right now'

Chris Narine, a resident, said he actually considered himself lucky because his apartment unit was not damaged by the fire.

"I'm lucky, but I'm still not lucky because there's nowhere to go to live right now. My unit is okay, but my neighbour's, everything is done," he said as he left the building

"Maybe tomorrow, I'll go to my daughter for awhile. Then after that, I'll see what I can do and go from there. Tonight, I'll stay in the bus."

Overnight: <a href="https://twitter.com/Toronto_Fire?ref_src=twsrc%5Etfw">@Toronto_Fire</a> had to fully evacuate the apartment building affected by yesterday's 5-alarm fire on Gosford Blvd, due to issues w/ the hydro system. Deputy Chief Jim Jessop says crews did an exceptional job extinguishing the fire & rescuing people. <a href="https://twitter.com/TPFFA?ref_src=twsrc%5Etfw">@TPFFA</a> <a href="https://twitter.com/ChiefPeggTFS?ref_src=twsrc%5Etfw">@ChiefPeggTFS</a> <a href="https://t.co/uh8jjMtPpL">pic.twitter.com/uh8jjMtPpL</a> —@JeremyCohnTV

Earlier, Toronto Fire Chief Matthew Pegg said electricity to the building had to be disconnected and all tenants moved out for safety reasons.

Originally, many residents were allowed to shelter in place, but the Electrical Safety Authority decided that power had to be cut.

Pegg also expressed condolences to the family that lost a loved one in the fire.

"Our thoughts and prayers are with the family and those affected by this tragic loss," he said in a tweet.

Actions by firefighters described as 'heroic'

Toronto Deputy Chief Jim Jessop told reporters at the scene early Saturday that firefighters worked throughout the night to bring the blaze under control and he described their efforts as "heroic."

About 100 firefighters and 22 trucks were involved in fighting the fire.

Ontario's Fire Marshal has been notified about the fire. An investigation is underway into its cause, where it started and the circumstances that contributed to its spread.