The Saskatoon Fire Department (SFD) said it received a residential fire signal from the building at 530 25th St. E. at 3:23 p.m.
Nothing was showing from the exterior of the building when crews arrived, but a check found smoke on the third floor from a fire in a suite, SFD said.
The building was evacuated and residents were taken to the neighbouring YWCA building. Tenants with mobility issues were sheltered in their suites.
The fire department said the building’s sprinkler system put out the fire prior to their arrival, but heavy smoke remained throughout the third floor.
Higher carbon monoxide levels were reported on the third floor and above, SFD said, and positive pressure ventilation was used on each floor to remove smoke and toxic gasses.
Residents were allowed back to their apartments once carbon monoxide levels returned to zero.
A fire investigator determined a candle ignited stationary on a desk, starting the fire.
Damage is estimated at $100,000 due to the significant amount of water discharged from the sprinkler system.