A Burlington church sustained heavy damages after a fire broke out overnight. Now, investigators are trying to figure out how it started and are looking into a possible link to graffiti spray-painted on the church.

They say it's being treated as suspicious and Ontario Fire Marshal investigators have been on the scene. 

Halton police got a call about a fire at Trinity Baptist Church at 4372 Appleby Line at around 1:18 a.m. Wednesday morning.

Flames could be seen shooting out of the church's roof when emergency crews arrived.

Deputy Fire Chief Ross Monteith told CBC News that the fire started on the outside back corner of the structure, and then extended into the attic space of the old church.

Burlington church fire

A fire broke out at Trinity Baptist Church in Burlington overnight. (Tony Smith/CBC)

The church is broken up into two main buildings, with additions built on through the years to an existing older structure.

"We did send crews into the interior and try to attack the attic space," Monteith said. "But [that area] is difficult to get to in any building, and especially so here."

'Heartbreaking to see the thing go up in flames'

Pastor Carl Muller got a call about the fire at 1:30 a.m. and got to the church close to 2.

"We've been worshipping in that place for a long time," Muller said. "And so it's really quite heartbreaking to see the thing go up in flames."

There's no damage to the newer part of the building, built in 2004, beyond some smoke and water damage. Muller said the church is grateful for the "tremendous work" the fire department did in the effort.

Muller said he's worked at the church since the late 1980s.

'ISIS' spray-painted on building

Another element of the vandalism is hard to miss.

"They wrote 'ISIS' in three spots on the outside of the building," Muller said. "It's black spray paint, pretty big. You can clearly see it from a distance."

He said he is trying not to jump to conclusions as police and the fire marshal investigate.

Det. Sgt. Ron Hansen with Halton police said they cannot say for certain that the graffiti was connected to the fire, but said "we cannot rule it out either."

"Our investigation is continuing in conjunction with the Ontario Fire Marshall's Office and it is more likely that the graffiti was done to increase the public interest in the fire," Hansen said.

'I'd be surprised if ISIS targeted us'

Muller shares that assessment.

"If they do find that someone did it, my suspicion would be that it's just malevolent vandalism – people who, in a mischievous way, just decided to write ISIS on it," Muller said.

"I'd be surprised if ISIS targeted us. We're small fish, you know?" he said.

"I just think it's some malevolent, small-minded people who have done this. I hope they catch them, if in fact it was arson."

He said he would like to have a chance to talk with the people involved and share what the church believes.

Cause undetermined

Firefighters did manage to eventually get the fire out, and were still on scene Wednesday morning watching for hotspots. Police say the church "suffered extensive damage." No one was injured.

"[The cause] is undetermined at this point, but starting on the outside like it did and at that time of the morning with no one around lends itself to suspicion," he said. 

Burlington church fire

Police say it's too early to know what caused the fire. (Tony Smyth/CBC)

No exact dollar figure has been attached to the damages, but Monteith said if he was to estimate, it would likely exceed $500,000. 

The church's website says the congregation's history stretches back to the early 1970s. The frst official Sunday services of the church were held at Trefoil Lodge on Brant Street, before purchasing the old United Church building on Appleby Line in 1975.

Additions and renovations were done over the next couple of decades.

Anyone with information about the incident is asked to contact the Burlington Fire Department or Halton police at 905-825-4747 ext. 2316.

adam.carter@cbc.ca