POST FALLS - A suspicious fire inside an outbuilding on the north side of Post Falls on Thursday prompted the need for outside agencies to be called upon to investigate.

The fire at 10937 W. Prairie Ave., just east of the intersection of Idaho and Prairie, was reported by a passerby at 5:48 a.m. It was contained to the inside of the building. There were no injuries and the cause is under investigation. The property owner is Casey Downs.

"There's enough in question as far as a cause for us to bring in outside resources to assist with the investigation," said Jim Lyon, Kootenai County Fire and Rescue spokesman.

Due to fire origin of a suspicious nature, an investigator from the State Fire Marshal's office and an investigation canine team from Spokane Valley Fire was called to help investigate.

Mako, a black lab, is trained specifically for fire investigations and to detect accelerant.

There were no people or animals in the building when the fire was reported, Lyon said.

Lyon said the fire caused damage to the kitchen area, flooring and walls. There was also smoke damage throughout, including to couches. Firefighters said it appeared the building was being remodeled.

"The fire was extinguished pretty quickly, and structurally the building is still sound," Lyon said. "It was pretty sparsely furnished."

Lyon said there were no vehicles or any other large items of significant value in the single-story building with metal siding that's about 2,500 square feet.

No other structures were threatened, including a home about 150 feet away.

Coeur d'Alene Fire and Northern Lakes assisted.