Investigators are working to determine the cause of a fire that damaged a building in Northampton County late Sunday night.

The fire started around 10 p.m. on the second floor of the building on Route 512 in Moore Township, according to the Klecknersville Fire Company.

Crews were able to put out the flames in about three hours.

Neighbors said the flames consumed the top floor.

"I saw cops sitting here. I didn't know what was going on, and then I heard more sirens coming down 512. I looked out the sun room and saw the flames shooting up," a neighbor said.

According to neighbors, the building was a former antique shop that closed about 10 years ago. They said it was also a former shed building business.

"They used to have antiques in there and it used to be the office when they sold sheds," a neighbor said.

Neighbors were not sure how the building was being used at the time of the fire.