There have been 18 reported structure fires since May 2011. All but one of them are believed to be connected, and some broke out in the same location more than once.
The latest suspicious fire started around midnight Sunday at the old Lipton Tea factory in the 500 block of Main St.
Streator firefighters were battling another suspicious fire in the 300 block of Vermillion St. when a call came in for the factory fire.
Additional help was requested, and ultimately 13 fire departments spent several hours putting out the flames.
This YouTube video shows the fire and smoke billowing out of the historic, 4-story building that has been a community staple since the 1900's.
On Monday, Mayor Jimmie Lansford called a news conference to update reporters and the public on the string of fires.
Lansford and other officials said the fire started on the factory's second and third floor. But what is unclear is how it started.
The building was only used for storing pluming materials.
Officials said it appears the fire is connected to 16 other fires they believe were intentionally set.
"Sooner or later somebody will make a mistake and they will be caught, and that's our intent. Our intent is to find out who has been doing these crimes, catch them, put them in the system and convict them with the stiffest penalty possible," Lansford said.
It was also revealed Monday a firefighter was treated and released for a shoulder injury sustained in the fire.
Because someone was hurt, charges against any suspect could be amplified to aggravated arson.
Officials said they have no suspects at this time. They said they are getting credible tips, but nothing has come of them yet pertaining to Streator's arson problem.
People are asked to keep their eyes peeled and report any suspicious activity to police at (815) 672-2266.
Meanwhile, the factory fire is what people are buzzing about in Streator.
Not only are they sad to see history destroyed, they're also fed up with whoever police say is targeting their community.
A steady crowd gathered near the building Monday to see and take pictures of the damage.
Streator resident Ralph Trainor brought his camera and said, "(This is) one of the old ones in town left and that's it."
The landmark is charred and collapsing, which made Trainor think its days are numbered.
"This place will be gone now," he said.
Two nights before Trainor watched as the fire tore through the building.
"I saw all the trucks and that's when I seen Lipton Tea on fire, and I went and told my wife Lipton Tea's on fire," he recalled.
Others in the crowd lamented the building's demise, saying it's a tragic end to a place that holds a lot of memories.
Streator resident James Morris said, "It's a major building in town. A beautiful looking building, a nice brick building."
Like so many central Illinois towns, Streator uses Main St. for its parades and other events. And people say the building made for the perfect backdrop.
"The car show uptown, the parades. It's always been there," Morris said.
Now the building is the latest in a strong of potential arsons. The situation is making many residents feel uneasy.
Some even voiced their opinions at the news conference.
"What are neighbors supposed to do who are living next to these abandoned buildings," one woman asked.
"You see something like that going on. It's just frustrating," Morris said.
Trainor worried, "What do you do if one of these would've caved in and landed on a fireman or something. Somebody could've got killed."
People are hoping officials catch who's responsible before something else in town goes up in flames.
The factory was built in the 1900's. Lipton left Streator in the 1960's.
A fire official says the building is extremely unstable.
Engineers are trying to figure out what to do next.