A 73-year-old man is dead and at least five others are injured after a two-alarm fire broke out at a seniors' residence in Ottawa's east end Thursday morning.

Officials say flames broke out in a third floor room shortly after 10 a.m., blasting open a window, filling the corridors with smoke and forcing the evacuation of 119 residents and staff at Rothwell Heights, a privately-run supported living home on Montreal Road.

An elderly man who lived in the third floor room where the fire apparently started was pronounced dead at the scene. His name will not be released until next of kin are notified.

Four other residents were treated for minor smoke inhalation and one firefighter suffered an ankle injury during the blaze.

A spokesperson for the Ottawa paramedics said the quick actions of Rothwell Heights' staff members prevented the situation from becoming much worse.

"A lot of them have mobility issues so we certainly right now credit the work of the nursing home staff here for getting those residents out. Even from the outside you can see quite a bit of damage, even smoke damage on the outside of the building - so you can just imagine the inside of the building," J.P. Trottier told CTV Ottawa.

Many of the building's residents - about 90 per cent of whom are subsidized by the City of Ottawa - were sent to old Vanier City Hall and Laurier Manor, a long-term care facility located next door, while crews continued clean up efforts Thursday morning.

"We have a reciprocal agreement with our neighbours in the event of an emergency that we would house on a temporary basis a number of residents," said Kris Guty a spokesperson for Laurier Manor.

Returning home

All residents living in the building remained evacuated from the premises Thursday night. Although officials said those living on the first and second floors may be able to return to their homes within days, residents on the third floor likely won't be able to return to their units for weeks due to the extent of the damage.

In the meantime, the city's emergency social services department has temporarily sent 38 residents left homeless by the fire to the Vanier Richelieu Community Centre until family members can pick them up.

"If not, we do have another 50 beds available in the city where we can relocate them, So, at the moment we're somewhat waiting to see what the situation will unfold at this site with what the two facilities can muster as far as beds for the affected individuals," said Dan Brisebois of Ottawa emergency social services.

Assessing the damage

Firefighters continued to assess smoke and heat damage to the building Thursday afternoon.

Although there is no word on the cause of the fire, staff members at the residence said a man had been smoking in his room before the fire alarm went off.

"We had spoke with him several times and we had taken his cigarettes out of his room at that time, but it's independent living in our home and so people do go buy more," said Dorothy Vlaming, owner of the facility.

Ottawa police and the Ontario Fire Marshal's office are continuing their investigation.

With a report from CTV Ottawa's Vanessa Lee and Joanne Schnurr