A vacant Sherman house was destroyed by flames Wednesday night nearly three weeks after another fire occurred at the same residence.

Firefighters were called to the structure fire in the 700 block of South First Street at 6:50 p.m. Sherman Fire Marshal Danny Fuller said the house was fully engulfed when crews arrived, and they knew the structure was vacant so they turned their attention to keeping the fire from spreading.

Fuller said the flames were under control about 10 minutes after crews arrived and fully contained in about 30 minutes. The fire destroyed the house. Fuller said the cause appears to be suspicious.

Firefighters were called to extinguish flames at the same house on Oct. 16. Fuller said that fire started in the front porch area, and caused extensive damage. The cause of that fire is still under investigation, but it was suspicious and investigators are waiting for results to see if accelerants were used. He said they have general descriptions of people tied to the first fire.

“The individuals that we’re looking for we don’t really have good clear identification yet and as soon we get those clarified, we’re hoping to be able to speak to them and question them,” Fuller said.

The origin and cause of Wednesday’s fire is still being determined, but Fuller said the house did not have any utilities. He recommends owners of vacant properties make sure those structures are secured so firefighters won’t need to extinguish intentional fires.

“Each time we respond — it’s dangerous for firefighters to respond and to actually mitigate and protect exposure to neighbors,” Fuller said.