VERNON, Conn. (WTNH) – Nine months after a four-alarm fire destroyed a historic mill in Vernon, investigators are calling it suspicious and asking for the public’s help in identifying a vehicle seen near the building.

The fire started around 2 a.m. on Dec. 12, 2022, at 114 Brooklyn Street. No injuries were reported, but part of the factory collapsed due to the flames. These damages resulted in the demolition of the building built in 1862.

At a Tuesday morning press conference, Vernon police Lt. Robert Marra said they are looking for a dark blue or green pickup truck that may be a Dodge Ram.

VIDEO: Vernon police release surveillance video of pickup truck seen near mill before and after fire

Marra said the pickup was seen circling Brooklyn Street multiple times and leaving shortly after the fire was set. At one point, he said, two people exited the vehicle and appeared to enter the mill minutes before the fire started.

“There is somebody that gets out of the vehicle and gets into the mill, and shortly after, it’s up in flames,” Marra said.

“Acting suspiciously, lights off in the vehicle and had come around the block several times, it raised our suspicion,” Vernon Fire Administrator Daniel Wasilewski said.

Police said the investigation has hit a dead-end after months of combing through surveillance video and talking to witnesses.

“We’re out of leads at this point,” Marra said.

Vernon police are offering a $10,000 reward for information that leads to an arrest in the case.

The property had recently switched ownership, and investigators said the new owner planned to renovate the 1862 mill building. It was vacant at the time of the blaze, except for a machine shop on one floor that police said hindered the investigation.

“Many of the things the dogs would have hit on are common in a machine shop, cutting oil, fluids, that could be used as an accelerant are common,” Wasilewski said.

He said the building burned for 12 hours, making it impossible to determine where or how the fire started.

Over a dozen nearby homes were evacuated as the fire stretched across Brooklyn Street, damaging several houses.

“The fire was spreading fast,” neighbor Takisha Johnson, who called 911, said. “I was scared. When we came out of the house, it was that hot. It melted the siding.”

“This was a middle-of-the-night fire with a lot of homes nearby,” Wasilewski said. “Those homes very luckily didn’t catch fire that night due to a quick response from the fire department, but many lives could have been lost here.”

Police said they do not have enough evidence to deem the fire an arson, so it is now categorized as suspicious.

Anyone with information on the vehicle, its occupants or the fire should contact Vernon Police Det. Mike Patrizz at (860) 872-9126 ext. 3763. Tips can also be called into the Connecticut Arson Tip Line at 1-800-84ARSON.