The cause of a Tuesday night fire on Duke Street in Summerside remains under investigation but it is suspicious, the Summerside Fire Department says. 

Firefighters were called to the blaze at a story-and-a-half building at 162 Duke St. around 9 p.m.

Fire Chief Jim Peters said the home is unoccupied. 

"The upper portion of the building received heavy damage and there was water damage throughout the rest of the house. Station 1 responded with three pumpers and a ladder truck and we were there for about an hour fighting the fire," Peters said. "Right now, (the cause) is looking suspicious."

Peters said officials from the provincial Fire Marshall's office, as well as Summerside Police Services, are on the scene investigating.