A Kailua apartment fire early this afternoon caused $20,000 damage and has displaced a woman and her dog.

The fire at a studio apartment behind an older single-family home on Keaniani Street was reported by neighbors who heard the crackling sounds of the flames, said Capt. Terry Seelig, Honolulu Fire Department spokesman.

The home had no smoke alarm system, which delayed detection and could have contributed to a higher amount of damage, Seelig said.

Three engines and a ladder truck responded to the 12:46 alarm but only two remained to douse the flames and put out the fire by 1 p.m., he said.

The Red Cross was contacted to help the woman resident, who was not home at the time. The dog was not in the apartment.