Ottawa Fire were called to what appeared to be an electrical blaze at a Donald St. apartment building Monday.
It broke out late in the morning, prompting an evacuation of the ninth and tenth floors at 1244 Donald.
Firefighters had to call a second alarm.
Three people caught on their balconies needed to be reached by ladder.
They were safely escorted out through the building.
Donald St. was blocked off between Cummings and St. Laurent
It has since reopened.
The fire left floors nine through 17 uninhabitable. The Red Cross says 199 people have been registered for assistance.
Hotel rooms have been arranged for the displaced, and the building management has paid for dinner for affected residents.
Ottawa Fire is hopeful to have power restored in the building by Tuesday, to allow as many affected residents as possible to return home.