WAUKESHA, Wis. (CBS 58) -- The Waukesha Fire Department responded to an apartment complex fire on Sunday, Oct. 20. 

It happened around 2:41 p.m. at a 16-unit building on Kensington Drive.

Initial callers saw the fire on the outside of the building that then spread to the inside of the attic. Crews worked to evacuate the building. No residents were hurt. 

One firefighter was treated for a minor injury related to heat stress, but did not go to the hospital. 

The fire department said that one cat was found dead, and the fire department continues to search for a cat that is unaccounted for. 

After the fire was put out, the roof was destroyed, but there is no word on how many people are now displaced from the fire. There is no damage estimate at this time. 

Police and fire investigators are working to determine exact the cause of the fire.