The Calgary Fire Department was called to a basement fire in the southeast of the city around noon Friday.
When crews arrived at the fire in Southview on the 2000 block of 36 St. S.E., a large amount of dark smoke was seeping from the windows of the residence.
Four occupants of the residence had exited the building by jumping off the balcony, as their exit was blocked by the smoke and fire.
All were assessed by EMS and found to have no injuries.
Fire crews believe the fire started in the basement before it extended to the main floor, causing extensive damage.
A Calgary Transit bus was brought in to provide shelter for six other residents and two dogs.
Three other suites in the building did not sustain damage, and the residents have been allowed back into the building.
The four displaced residents are being assisted by the Red Cross.
Calgary Fire says the residents were alerted to the fire by a working fire alarm; and would like to remind citizens on the importance of having working fire alarms and a home escape plan.
A fire detector should be installed in each level of a home and should be tested one time per month. Alarms should be replaced after 10 years.
They also recommend to practice a home escape plan twice every year.