CEDAR RAPIDS, Iowa (KCRG-TV9) -- Firefighters were called to 903 E Avenue NW at 5:49 p.m. Monday.
When authorities arrived on scene they found smoke coming from the eaves and fire showing in second story windows of the two-story residential building with rental units inside.
Firefighters were able to create a "Fast Attack" along with coordinated ventilation through a vent hole in the roof to bring the fire under control.
Police say all occupants were accounted for and were not hurt in the fire. However, four occupants were displaced from the damage.
The first firefighters on scene and witnesses said the air conditioner was on fire in a window of the building and actually fell to the ground.
An investigation determined the fire was started with the air conditioner and an extension cord the unit was plugged into.
The firefighter investigator said the extension cord was a heavy-duty one and the failure could've been from the cord or the air conditioner unit itself.
The fire is still under investigation and the Fire Department recommends all appliances are plugged directly into an outlet.