UTICA, N.Y. (WKTV) - A Sunday night fire at an Albany Street apartment building was intentionally set, fire officials said.

Although the fire broke out around 9:30 p.m. Sunday night, the Utica Fire Marshal's Office said that fire investigators remained on the scene of the 515 Albany Street fire until 1 a.m. Monday morning conducting an investigation.

At the conclusion of their investigation, it was determined that the fire originated on the exterior of the rear addition.

The fire extended up the rear wall and into the attic causing severe fire damage to the rear of the first floor, second floor and attic of the addition. Smoke and water damage were reported in the second floor apartment of the main structure.

The building was vacant at the time of the fire and officials said that all utilities were disconnected prior to the fire.

Investigators said the fire has been ruled incendiary.